Possible Causes of High or Low Red Blood Cell Count

  1. Abnormal Blood Counts | Froedtert & the Medical College of Wisconsin
  2. Anemia (Low Red Blood Cells)
  3. Leucopenia (Low White Blood Cells)
  4. Thrombocytopenia (Low Platelets)
  5. Immune Thrombocytopenia (ITP)
  6. Heparin-Induced Thrombocytopenia
  7. Gestational Thrombocytopenia
  8. Pancytopenia (Low Blood Cells)
  9. Polycythemia (High Red Blood Cells)
  10. Leucocytosis (High White Blood Cells)
  11. Thrombocytosis (High Platelets)
  12. Monoclonal Gammopathy of Undetermined Significance (MGUS)
  13. RBC Count: Tests That Measure Oxygen-Carrying Red Cells in Blood
  14. Anemia of Inflammation or Chronic Disease | NIDDK
  15. Why is anemia of inflammation also called anemia of chronic disease?
  16. Are there other types of anemia?
  17. How common is anemia of inflammation?
  18. Who is more ly to have anemia of inflammation?
  19. Does anemia of inflammation lead to other health problems?
  20. What are the symptoms of anemia of inflammation?
  21. What causes anemia of inflammation?
  22. Chronic conditions that cause anemia of inflammation
  23. Other causes of inflammation that may lead to anemia
  24. How do health care professionals diagnose anemia of inflammation?
  25. Medical history
  26. Blood tests
  27. How do health care professionals treat anemia of inflammation?
  28. Treating the underlying condition
  29. Medicines
  30. Blood transfusions
  31. Can I prevent anemia of inflammation?
  32. How does eating, diet, and nutrition affect anemia of inflammation?
  33. Clinical Trials for Anemia of Inflammation
  34. What are clinical trials for anemia of inflammation?
  35. What clinical studies for anemia of inflammation are looking for participants?
  36. References
  37. Polycythemia Vera
  38. Anemia
  39. About red blood cells
  40. Signs and symptoms
  41. Causes of anemia
  42. Diagnosing anemia
  43. Treating anemia
  44. Blood transfusion
  45. Medications
  46. Vitamin or mineral supplements
  47. Related Resources
  48. More Information
  49. Polycythemia Vera Diagnosis | Leukemia and Lymphoma Society
  50. Medical History and Physical Examination
  51. Blood Tests
  52. Bone Marrow Tests
  53. Molecular Testing
  54. Criteria for Diagnosing Polycythemia Vera
  55. Related Links
  56. Red Blood Cell Count – Understand Your Tests & Results

Abnormal Blood Counts | Froedtert & the Medical College of Wisconsin

Possible Causes of High or Low Red Blood Cell Count

Blood is composed of red blood cells, white blood cells and blood platelets. These cells and cell fragments are suspended in blood plasma.

Abnormal amounts of these components can lead to several symptoms and health problems. These abnormalities can also be caused by an underlying disease. Abnormal blood counts are common and are often very treatable.

In rare cases, an abnormal blood count can indicate an immune disorder or a cancer.

Physicians in the Benign Hematology Program specialize in evaluating patients with abnormal blood counts to identify the cause of their condition and create a personalized treatment plan.

Anemia (Low Red Blood Cells)

Red blood cells contain hemoglobin, a protein that enables the blood to carry oxygen to every part of the body. Anemia develops when the body does not produce enough red blood cells or red cells are lost due to bleeding or other causes. In people with anemia, the blood is unable to supply enough oxygen to the body.

There are many possible causes of anemia. Symptoms of anemia can include:

  • Fatigue
  • Weakness
  • Dizziness
  • Headache
  • Irritability
  • Shortness of Breath (severe cases)
  • Chest Pains (severe cases)

Anemia can be a temporary problem or a chronic condition. Milder anemia can be treated with dietary changes, iron replacement (oral or IV) and vitamin supplementation.

Patients with more severe anemia may receive various medications to boost red cell production or inhibit red cell destruction. Patients with very low red blood cell counts may require blood transfusion.

Leucopenia (Low White Blood Cells)

Patients with low white cell counts are more vulnerable to infections. Leucopenia can be caused by infections, certain medications and several underlying conditions, including immune disorders rheumatic arthritis and lupus and cancers such as leukemia and lymphoma. 

Treatment for leucopenia can include drugs that stimulate the body to produce white blood cells.

Thrombocytopenia (Low Platelets)

Low blood platelets can lead to abnormal bruising and bleeding. Thrombocytopenia can be caused by several different conditions:

Immune Thrombocytopenia (ITP)

Immune thrombocytopenia (ITP) is a condition in which the body produces antibodies that attack platelets. ITP is the most common cause of low platelet counts.

Heparin-Induced Thrombocytopenia

Heparin-induced thrombocytopenia is a potential side effect of heparin, a blood thinner medication used to treat blood clots. An immune reaction to the drug causes blood clots to form.

Gestational Thrombocytopenia

Gestational thrombocytopenia is a mild condition that can arise during pregnancy. Learn more about pregnancy, menstruation and blood disorders.

Abnormal bleeding and bruising can also be caused by a bleeding disorder  Von Willebrand disease.

Treatment of thrombocytopenia depends on the specific cause. Steroids can be used to calm down immune-related reactions. Several medications can be used to raise platelet counts. Some patients are treated with blood transfusion.

Pancytopenia (Low Blood Cells)

Pancytopenia is marked by low counts of all three types of blood cells—red cells, white cells and platelets. This condition can be caused by certain medications and by infections. In some cases, it is caused by a cancer or precancerous condition. Myelofibrosis, bone marrow scarring that can result from various hematologic cancers, typically leads to low blood counts.

Pancytopenia can also be caused by aplastic anemia, a bone marrow failure disorder that affects blood cell production.

Polycythemia (High Red Blood Cells)

Polycythemia vera is a low-grade cancer marked by the overproduction of red blood cells. Elevated production of red blood cells can also occur in response to low levels of oxygen within body tissues. Treatment can include medications to reduce the risk of clotting. In some cases, patients undergo regular phlebotomies (blood draws) to reduce blood cell counts.

Leucocytosis (High White Blood Cells)

The most common causes of elevated white blood cell counts are infections and inflammation. Some cases of leucocytosis are the result of an immune reaction. A small number of cases are caused by a blood cancer. Treatments for high white blood cell counts typically focus on addressing the underlying disease.

Thrombocytosis (High Platelets)

High blood platelet counts can be caused by several conditions, including anemia, cancer, inflammation and infection. Treatment usually focuses on the underlying condition or disease. Essential thrombocythemia (ET) is a rare disease in which the bone marrow produces too many platelets. Patients may receive medicines to lower their risk of blood clots and reduce platelet counts.

Monoclonal Gammopathy of Undetermined Significance (MGUS)

MGUS is a condition characterized by abnormal plasma cells. Although it is not a cancer, it is closely related to multiple myeloma.

Source: https://www.froedtert.com/benign-hematology/conditions/abnormal-blood-counts

RBC Count: Tests That Measure Oxygen-Carrying Red Cells in Blood

Possible Causes of High or Low Red Blood Cell Count

The red blood cell (RBC) count is used to measure the number of oxygen-carrying blood cells in a volume of blood. It is one of the key measures we use to determine how much oxygen is being transported to cells of the body.

An abnormal RBC count is often the first sign of an illness that may either be undiagnosed or without symptoms. At other times, the test can point the doctor in the direction of a diagnosis if there are symptoms, such as shortness of breath or fatigue, which cannot be readily explained.


Typically speaking, an RBC count is less useful on its own to diagnose a medical condition. Instead, it is most often performed as part of a more comprehensive test called a complete blood cell (CBC) count which measures the composition cells in a blood sample. They include:

  • Red blood cells (RBC) which transport oxygen to cells of the body
  • White blood cells (WBC), which are a part of the immune system
  • Hemoglobin (Hb), a protein which carries oxygen and carbon dioxide molecules
  • Platelets (PLT), the cells responsible for blood clotting
  • Hematocrit (Hct), the ratio of RBC to the total volume of blood

the composition of blood cells, doctors can better know where to focus their investigation and which areas they can probably avoid.

An RBC count is the number of red blood cell per a particular volume of blood. It may be reported in millions of cells per microliter (mcL) of blood or in millions of cells per liter (L) of blood.

The “normal” range can sometimes vary by population. Many reference values will be far higher in high-altitude cities Denver and far lower in low-altitude areas the Gulf Coast. As such, the ranges cannot be considered hard-and-fast values but rather, as the name suggests, a reference point.

The “normal” RBC reference range for women is 4.2 to 5.4 million/mcL; for men, 4.7 to 6.1 million/mcL; for children, 4.0 to 5.5 million/mcL.

A high RBC count tells us that there has been an increase in oxygen-carrying cells in blood. This usually indicates that the body is compensating for some condition that is depriving the body of oxygen, including:

A low RBC count indicates a decrease in oxygen-carrying cells in the blood. The causes can be many, ranging from infections and deficiencies to malnutrition to malignancies, including:

  • Anemia
  • Kidney failure
  • Thyroid problems
  • Bleeding, internal or external
  • Leukemia, a type of blood cancer
  • Drug side effects, including chemotherapy
  • Multiple myelomas, a type of cancer affecting plasma cells
  • Erythropoietin deficiency, a kidney hormone that promotes RBC growth
  • Deficiencies in iron, folate, vitamin B12, or vitamin B6
  • Hemolysis, the abnormal breakdown of red blood cells
  • Pregnancy

Inasmuch as an RBC count can help diagnose a medical condition, it's also used to monitor treatment. If you've been diagnosed with a blood disorder or are taking any medications that affect your RBC, your doctor will want to monitor this as a matter of course.

This is especially true for cancer and cancer chemotherapy, both of which can have a detrimental cause-and-effect impact on blood counts.

Treatment of an abnormal RBC count is typically focused on treating the underlying condition, whether it be an infection, injury, cancer, or a genetic disorder.

If, on the other hand, the cause is related to a nutritional deficiency, medication use, or a chronic condition, there may be things you can do to not only improve your blood count but your overall health, as well.

If you have a high RBC count:

  • Exercise to improve heart and lung function.
  • Eat less red meat and iron-rich foods.
  • Avoid iron supplements.
  • Keep yourself well hydrated.
  • Avoid diuretics, including coffee and caffeinated drinks.
  • Stop smoking, especially if you have COPD or pulmonary fibrosis.
  • Avoid the use of steroids and other performance-enhancing drugs.

If you have a low RBC count (including anemia):

  • Maintain a healthy, balanced diet.
  • Take a daily vitamin and iron supplement, if needed.
  • Exercise regular to improve heart and lung function.
  • Stop smoking.
  • Avoid aspirin which can thin blood.
  • Take your thyroid medications as prescribed if you have thyroid problems.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. George-Gay B, Parker K. Understanding the complete blood count with differential. J Perianesth Nurs. 2003;18(2):96-114. doi:10.1053/jpan.2003.50013

  2. Leukemia & Lymphoma Society. Understanding Blood Counts.

  3. National Heart, Blood, and Lung Institute. Iron-Deficiency Anemia.

Additional Reading

  • American Association for Clinical Chemistry/Lab Tests Online. Red Blood Cell Count (RBC). Updated April 10, 2019.
  • Bunn, H. “Chapter 158: Approach to the anemias.” In: Goldman L, Schafer AI, Eds. Goldman's Cecil Medicine (25th edition). Philadelphia: Elsevier Saunders; 2015.
  • Goljan EF. “Chapter 12: Red blood cell disorders.: In: Goljan E, ed. Rapid Review Pathology (4th edition). Philadelphia: Elsevier Saunders; 2014.

Source: https://www.verywellhealth.com/red-blood-cell-rbc-count-1942659

Anemia of Inflammation or Chronic Disease | NIDDK

Possible Causes of High or Low Red Blood Cell Count

Anemia of inflammation, also called anemia of chronic disease or ACD, is a type of anemia that affects people who have conditions that cause inflammation, such as infections, autoimmune diseases, cancer, and chronic kidney disease (CKD).

Anemia is a condition in which your blood has fewer red blood cells than normal. Your red blood cells may also have less hemoglobin than normal. Hemoglobin is the iron-rich protein that allows red blood cells to carry oxygen from your lungs to the rest of your body. Your body needs oxygen to work properly. With fewer red blood cells or less hemoglobin, your body may not get enough oxygen.

In anemia of inflammation, you may have a normal or sometimes increased amount of iron stored in your body tissues, but a low level of iron in your blood. Inflammation may prevent your body from using stored iron to make enough healthy red blood cells, leading to anemia.

Anemia is a condition in which your blood has fewer red blood cells or less hemoglobin than normal.

Why is anemia of inflammation also called anemia of chronic disease?

Anemia of inflammation is also called anemia of chronic disease because this type of anemia commonly occurs in people who have chronic conditions that may be associated with inflammation.

Are there other types of anemia?

There are many types of anemia. Common types include

  • iron-deficiency anemia, a condition in which the body’s stored iron is used up, causing the body to make fewer healthy red blood cells. In people with iron-deficiency anemia, iron levels are low in both body tissues and the blood. This is the most common type of anemia.
  • pernicious anemia, which is caused by a lack of vitamin B12.
  • aplastic anemia, a condition in which the bone marrow doesn’t make enough new red blood cells, white blood cells, and platelets because the bone marrow’s stem cells are damaged.
  • hemolytic anemia, a condition in which red blood cells are destroyed earlier than normal.

How common is anemia of inflammation?

Anemia of inflammation is the second most common type of anemia, after iron-deficiency anemia.1

Who is more ly to have anemia of inflammation?

While anemia of inflammation can affect people of any age, older adults are more ly to have this type of anemia because they are more ly to have chronic diseases that cause inflammation. In the United States, about 1 million people older than age 65 have anemia of inflammation.2

Does anemia of inflammation lead to other health problems?

Anemia of inflammation is typically mild or moderate, meaning that hemoglobin levels in your blood are lower than normal but not severely low. If your anemia becomes severe, the lack of oxygen in your blood can cause symptoms, such as feeling tired or short of breath. Severe anemia can become life-threatening.

In people who have CKD, severe anemia can increase the chance of developing heart problems.

What are the symptoms of anemia of inflammation?

Anemia of inflammation typically develops slowly and may cause few or no symptoms. In fact, you may only experience symptoms of the disease that is causing anemia and not notice additional symptoms.

Symptoms of anemia of inflammation are the same as in any type of anemia and include

  • a fast heartbeat
  • body aches
  • fainting or feeling dizzy or light-headed
  • feeling tired or weak
  • getting tired easily during or after physical activity
  • pale skin
  • shortness of breath

What causes anemia of inflammation?

Experts think that when you have an infection or disease that causes inflammation, your immune system causes changes in how your body works that may lead to anemia of inflammation.

  • Your body may not store and use iron normally.
  • Your kidneys may produce less erythropoietin (EPO), a hormone that signals your bone marrow—the spongy tissue inside most of your bones—to make red blood cells.
  • Your bone marrow may not respond normally to EPO, making fewer red blood cells than needed.
  • Your red blood cells may live for a shorter time than normal, causing them to die faster than they can be replaced.

Chronic conditions that cause anemia of inflammation

Many different chronic conditions can cause inflammation that leads to anemia, including

In people with certain chronic conditions, anemia may have more than one cause. For example

  • Causes of anemia in CKD may include inflammation, low levels of EPO due to kidney damage, or low levels of the nutrients needed to make red blood cells. Hemodialysis to treat CKD may also lead to iron-deficiency anemia.
  • People with IBD may have both iron-deficiency anemia due to blood loss and anemia of inflammation.
  • In people who have cancer, anemia may be caused by inflammation, blood loss, and cancers that affect or spread to the bone marrow. Cancer treatments such as chemotherapy and radiation therapy may also cause or worsen anemia.

Other causes of inflammation that may lead to anemia

While anemia of inflammation typically develops slowly, anemia of critical illness is a type of anemia of inflammation that develops quickly in patients who are hospitalized for severe acute infections, trauma, or other conditions that cause inflammation.

In some cases, older adults develop anemia of inflammation that is not related to an underlying infection or chronic disease. Experts think that the aging process may cause inflammation and anemia.

How do health care professionals diagnose anemia of inflammation?

Health care professionals use a medical history and blood tests to diagnose anemia of inflammation.

Medical history

A health care professional will ask about your history of infections or chronic diseases that may lead to anemia of inflammation.

Blood tests

Health care professionals use blood tests to check for signs of anemia of inflammation, other types of anemia, or other health problems. A health care professional will take a blood sample from you and send the sample to a lab to test.

Blood count tests can check many parts and features of your blood, including

  • the number of red blood cells
  • the average size of red blood cells
  • the amount of hemoglobin in your blood and in your red blood cells
  • the number of developing red blood cells, called reticulocytes, in your blood

Some of these blood count tests and others may be combined in a test called a complete blood count. A blood smear may be used to examine the size, shape, and number of red blood cells in your blood.

A health care professional may also use blood tests to check the amount of iron in your blood and stored in your body. These tests may measure

  • iron in your blood
  • transferrin, a protein in your blood that carries iron
  • ferritin, the protein that stores iron in your body’s cells

A health care professional may diagnose anemia of inflammation if blood test results suggest that you have anemia, a low level of iron in your blood, and a normal level of iron stored in your body tissues.

If blood test results suggest you have anemia of inflammation but the cause is unknown, a health care professional may perform additional tests to look for the cause.

For a blood test, a health care professional will take a blood sample from you and send the sample to a lab.

How do health care professionals treat anemia of inflammation?

Health care professionals treat anemia of inflammation by treating the underlying condition and by treating the anemia with medicines and occasionally with blood transfusions.

Treating the underlying condition

Health care professionals typically treat anemia of inflammation by treating the underlying condition that is causing inflammation. If treatments are available that can reduce the inflammation, the treatments may cause the anemia to improve or go away. For example, taking medicines to treat inflammation in rheumatoid arthritis can improve anemia.


A health care professional may prescribe the erythropoiesis-stimulating agents (ESAs) epoetin alpha or darbepoetin alpha to treat anemia related to CKD, chemotherapy treatments for cancer, or certain treatments for HIV.

ESAs cause the bone marrow to make more red blood cells. Health care professionals typically give ESAs as shots and may teach you how to give yourself these shots at home.

A health care professional may prescribe iron supplements, given as pills or shots, to help ESAs work.

If you’re on hemodialysis, you may be able to receive intravenous (IV) ESAs and iron supplements during hemodialysis. Read more about treatments for anemia in CKD.

Blood transfusions

In some cases, health care professionals may use blood transfusions to treat severe anemia of inflammation. A blood transfusion can quickly increase the amount of hemoglobin in your blood and boost oxygen.

Can I prevent anemia of inflammation?

Experts have not yet found a way to prevent anemia of inflammation. For some chronic conditions that cause inflammation, treatments may be available to reduce or prevent the inflammation that can lead to anemia. Talk with your doctor about treatments and follow the treatment plan your doctor recommends.

How does eating, diet, and nutrition affect anemia of inflammation?

If you have a chronic condition that is causing anemia of inflammation, follow the advice of your doctor or dietitian about healthy eating and nutrition.

Clinical Trials for Anemia of Inflammation

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and other components of the National Institutes of Health (NIH) conduct and support research into many diseases and conditions, including blood diseases.

What are clinical trials for anemia of inflammation?

Clinical trials—and other types of clinical studies—are part of medical research and involve people you. When you volunteer to take part in a clinical study, you help doctors and researchers learn more about disease and improve health care for people in the future.

Researchers are studying many aspects of anemia of inflammation, including new treatments for this condition.

Find out if clinical studies are right for you.

What clinical studies for anemia of inflammation are looking for participants?

You can find clinical studies on anemia of inflammation at www.ClinicalTrials.gov.

In addition to searching for federally funded studies, you can expand or narrow your search to include clinical studies from industry, universities, and individuals; however, the NIH does not review these studies and cannot ensure they are safe. Always talk with your health care provider before you participate in a clinical study.


[1] Nemeth E, Ganz T. Anemia of inflammation. Hematology/Oncology Clinics of North America. 2014;28(4):671–681.

[2] Fraenkel PG. Anemia of inflammation: a review. The Medical Clinics of North America. 2017;101(2):285−296.

Source: https://www.niddk.nih.gov/health-information/blood-diseases/anemia-inflammation-chronic-disease

Polycythemia Vera

Possible Causes of High or Low Red Blood Cell Count

Polycythemia vera (PV) is a blood cancer that begins in the marrow of your bones, the soft center where new blood cells grow. It causes your marrow to make too many red blood cells so your blood is too thick. You may be more ly to have clots, a stroke, or a heart attack.

This disease gets worse slowly, usually over many years. It can be life-threatening if you don't get treatment, but the right care can help you live a long life.

Most people who have PV don’t get diagnosed until they’re 60 or older, usually after a routine blood test. But it can happen at any age. Men get it more often than women.

It's common to worry when you find out that you have cancer. Remember that everyone is different and that all cancers aren’t the same. With the support of your doctor, family, friends, and other people who have polycythemia vera, you’ll be in the best position to manage it.

Your bone marrow makes three types of blood cells:

Red blood cells carry oxygen, white ones fight infections, and platelets clot your blood to stop bleeding.

Most people with polycythemia vera have too many red blood cells. But it can also cause you to have too many white blood cells and platelets.

PV is caused by a gene (either JAK2 or TET2) that doesn’t work the way it should. Most ly, the problem happened over the course of your life. Rarely, parents can pass these faulty genes to children.

At first, you may not notice any problems. When they do show up, polycythemia vera symptoms can include:

You may also feel pressure or fullness below your ribs on your left side. This might mean PV has enlarged your spleen, an organ that helps filter your blood.

Blood clots can cause a heart attack, a stroke, or deep vein thrombosis (DVT). They might also make your liver or spleen larger. If your organs don’t get enough blood, you could have chest pain or heart failure.

Having too many red blood cells might cause stomach ulcers, gout, or kidney stones.

PV can also lead to more serious blood diseases acute leukemia or myelofibrosis. Acute leukemia is a blood cancer that gets worse quickly. Myelofibrosis is a condition in which your bone marrow fills with scar tissue.

Your doctor will start with a physical exam, including a check of your spleen. They’ll ask about your symptoms and see if your face is unusually red.

You may have some blood tests, including:

  • Complete blood count(CBC). Your doctor takes a sample of your blood and sends it to a lab, where a machine counts the number of red blood cells, white blood cells, and platelets. An unusually high number of any of these could be a sign of polycythemia vera.
  • Blood smear. Your doctor looks at a sample of your blood through a microscope. It's a way to check for other diseases that are sometimes linked to PV.
  • EPO level. This test measures how much of the hormone EPO is in your blood. EPO tells your bone marrow to make blood cells. People who have polycythemia vera have very low amounts of it.

You may also need a bone marrow biopsy. The results can show your doctor if your bone marrow makes too many blood cells.

For this test, your doctor will take samples of your marrow, usually from the back of your hip bone.

You lie down on a table and get a shot that will numb the area. Then, your doctor uses a needle to take out a small amount of bone marrow. It's an outpatient procedure, which means you don't have to stay overnight in a hospital. You can get it done in a clinic, a hospital, or your doctor's office.

Questions for your doctor

Before your appointment, it's a good idea to make a list of things to ask your doctor, such as:

  • Which treatment do you recommend?
  • What are the side effects?
  • How can I prevent complications?
  • Since I have polycythemia vera, am I more ly to have a stroke or heart attack?
  • How can I ease my symptoms?

If you don't have many symptoms, you might not need treatment for PV right away. Your doctor will keep a close watch on you.

If you do need treatment, it will be aimed at lowering the amount of red blood cells your body makes and preventing blood clots and other complications.

Your options include:

Phlebotomy. This is often the first treatment for people who have polycythemia vera.

Your doctor takes blood from your vein so you have fewer blood cells. It's a lot donating blood. After it's done, your blood will be thinner, and it’ll flow more easily. You'll usually feel better, too. Some symptoms will ease, headaches or dizziness.

Your doctor will decide how often you need phlebotomy. Some people with PV don’t need any other treatment for many years.

Low-dose aspirin. This keeps platelets from sticking together. That makes you less ly to get blood clots, which in turn makes heart attacks or strokes less ly. Most people with polycythemia vera take low-dose aspirin.

Medicine to lower blood cells. If you need more help, your doctor may prescribe hydroxyurea (Droxia, Hydrea), a pill that lowers your red blood count and eases symptoms.

Another drug, interferon alfa (Intron A), helps your immune system cut back on making blood cells. You might take busulfan (Busulfex, Myleran) or ruxolitinib (Jakafi) if hydroxyurea isn’t helpful or if it causes severe side effects.

If you have itching that doesn't go away, your doctor may give you antihistamines.

Keep yourself comfortable and as healthy as possible during treatment:

  • Don't smoke or chew tobacco. Tobacco narrows blood vessels, which can make blood clots more ly.
  • Get light exercise, such as walking, to help your circulation and keep your heart healthy.
  • Do leg and ankle exercises to keep clots from forming in the veins of your legs. Your doctor or a physical therapist can show you how.
  • Bathe or shower in cool water if warm water makes you itch.
  • Keep your skin moist with lotion, and try not to scratch.

There's no cure, but the right treatment can help you manage this disease for many years.

Talk to your friends and family about what you’re dealing with. You may also want to join a support group for people who’ve been in your position.

The MPN Research Foundation has more information about polycythemia vera. It can also help you find support groups.


FamilyDoctor.org: “Polycythemia Vera.”

National Cancer Institute: “Polycythemia Vera.”

National Organization for Rare Disorders: “Polycythemia Vera.”

MPN Research Foundation: “Polycythemia Vera.”

University of Iowa Hospitals and Clinics: “Polycythemia Vera.”

New York-Presbyterian Hospital: “Polycythemia Vera.”

Johns Hopkins Medicine: “Polycythemia Vera.”

National Heart, Lung, and Blood Institute: “How Is Polycythemia Vera Diagnosed?” “Polycythemia Vera.”

National Center for Advancing Translational Sciences: “Polycythemia Vera.”

Mayo Clinic: “Polycythemia vera.”

© 2020 WebMD, LLC. All rights reserved. Causes and Symptoms

Source: https://www.webmd.com/cancer/polycythemia-vera


Possible Causes of High or Low Red Blood Cell Count

Anemia is an abnormally low level of red blood cells. It occurs when:

  • The body does not make enough red blood cells.
  • The body loses blood.
  • The body destroys red blood cells.

It is common for people with cancer to have anemia. This is especially true for those receiving chemotherapy. Most people with anemia feel tired or weak. People with this symptom may have a harder time coping with the physical and emotional demands of treatment.

About red blood cells

Red blood cells contain hemoglobin. Hemoglobin is an iron protein that carries oxygen to all body parts. When red blood cell levels are too low, the body parts do not get enough oxygen. As a result, they cannot work properly.

Red blood cells are made in bone marrow. Bone marrow is the soft, spongy tissue found inside larger bones. A hormone called erythropoietin tells the body when to make more red blood cells. This hormone is made in the kidneys. Therefore, damage to bone marrow or the kidneys can cause anemia.

Signs and symptoms

Managing symptoms, which can include anemia, is an important part of cancer care and treatment. This is called palliative care or supportive care. Talk with your health care team about any symptoms you or the person you are caring for experience.

People with anemia may have some of these symptoms:

Causes of anemia

The following factors can cause anemia:

  • Chemotherapy. Chemotherapy damages bone marrow. But this is usually temporary, and anemia usually improves a few months after chemotherapy ends. Also, chemotherapy with platinum drugs may harm the kidneys. These drugs include cisplatin (Platinol) and carboplatin (Paraplatin).
  • Radiation therapy. Certain types of radiation therapy damage bone marrow:
    • Radiation therapy to large areas of the body
    • Radiation therapy to bones in the pelvis, legs, chest, or abdomen
  • Certain types of cancer. Leukemia, lymphoma, and multiple myeloma damage bone marrow. Also, cancers that spread to the bone or bone marrow may crowd out normal red blood cells.

  • Nausea, vomiting, and loss of appetite. Nausea and vomiting and loss of appetite may cause a lack of nutrients. The body needs these nutrients to make red blood cells. These include iron, vitamin B12, and folic acid.

  • Excessive bleeding. Sometimes, red blood cells are lost faster than the body is able to replace them. This may happen after surgery or if a tumor causes internal bleeding.

Diagnosing anemia

Doctors use a blood test to diagnose anemia. It is called a complete blood count test. The test results include the number of red blood cells. A red blood cell count is measured in several ways. The 2 most common measurements are hemoglobin and hematocrit. The hematocrit is the percentage of your blood that is made up of red blood cells.

People with specific types of cancer types or who are receiving certain cancer treatments may have regular blood tests. These tests look for anemia and other blood-related problems. If test results show that you have anemia, you may need additional tests to find the cause.

Treating anemia

Doctors treat anemia the cause and symptoms. Here are some examples:

Blood transfusion

If anemia causes symptoms, you may need a transfusion of red blood cells.


If chemotherapy causes anemia, your doctor may prescribe medications called erythropoiesis-stimulating agents (ESAs). Erythropoietin is a hormone made in the body naturally by the kidneys. It helps the bone marrow make more red blood cells.

ESAs are forms of erythropoietin that are made in the laboratory. They work by telling bone marrow to make more red blood cells. ESAs include epoetin alfa (Epogen, Retacrit, Procrit) and darbepoetin alfa (Aranesp). Epoetin and darbepoetin are equally effective for treating anemia from chemotherapy and have similar risks.  

Epoetin and darbepoetin are injected into the body in regular intervals. They can take several weeks to start working.

The American Society of Clinical Oncology (ASCO) and the American Society of Hematology (ASH) provide the following recommendations for using epoetin and darbepoetin:

  • When ESAs may be given. ESAs may be given to treat anemia in the following situations.
    • If you are receiving chemotherapy as a treatment to manage symptoms of the cancer, called a “palliative treatment.”
    • If you have low-risk myelodysplastic syndrome (MDS) even when chemotherapy is not being given. MDS is a disorder of the bone marrow that also may cause anemia.
  • When ESAs should not be used. ESAs are not recommended:

    • If you are not receiving chemotherapy
    • If you are receiving chemotherapy to cure the cancer
    • If your hemoglobin level is 10 g/dL or higher
  • How ESAs are given. ESAs should be given at the lowest dose needed to raise your hemoglobin level just enough for you to avoid a blood transfusion, which may be different depending on your circumstances. The dose may be lowered when that level is reached, or if your hemoglobin level increases more than 1 g/dL within 2 weeks.

    If your hemoglobin levels are not rising after 6 to 8 weeks, ESA treatment is not working and your doctor should stop ESA treatment.

  • Risks of ESAs. ESAs are linked with serious health risks, such as an increased risk of death and blood clots. Talk with your doctor about the possible risks and benefits of using ESAs.

    The risks and benefits should be compared with the risks and benefits of a red blood cell transfusion.

    You and your doctor should be especially cautious about using these drugs if you have a high risk of developing blood clots.

    Risk factors for developing a blood clot from ESAs include:

    • A previous blood clot
    • Recent major surgery
    • Long periods of bed rest or limited activity (such as being in the hospital)
    • Some types of chemotherapy and hormone therapy.
    • Some types of treatment for multiple myeloma (especially thalidomide [Thalomid] or similar drugs).

This information is  ASCO and ASH recommendations about treatment of anemia with ESAs. Please note that this link takes you to another ASCO website.

Vitamin or mineral supplements

If a lack of nutrients causes anemia, doctors may prescribe supplements. These include iron, folic acid, or vitamin B12. These supplements are usually pills taken by mouth. Occasionally, you may receive a vitamin B12 injection. This may help the body absorb the vitamin. Also, consider eating foods high in iron or folic acid.

Foods high in iron include:

  • Red meat
  • Beans (legumes)
  • Dried apricots
  • Almonds
  • Broccoli
  • Enriched breads and cereal

Foods high in folic acid include:

  • Asparagus
  • Broccoli
  • Spinach
  • Lima beans
  • Enriched breads and cereals

ASCO Answers Fact Sheet: Anemia (PDF)

When to Call the Doctor During Cancer Treatment

More Information

National Cancer Institute: Anemia (PDF)

Source: https://www.cancer.net/coping-with-cancer/physical-emotional-and-social-effects-cancer/managing-physical-side-effects/anemia

Polycythemia Vera Diagnosis | Leukemia and Lymphoma Society

Possible Causes of High or Low Red Blood Cell Count

While a person may have certain signs and symptoms of polycythemia vera (PV), laboratory tests are needed to confirm the diagnosis. Generally, a doctor will consider other conditions first.

Sometimes a condition called “secondary polycythemia” is causing the increase in red blood cells but, un PV, it does not begin in the bone marrow and is not a cancer. High red blood cell counts caused by secondary polycythemia are a reaction to another problem such as: 

  • High altitude
  • Disease that leads to low oxygenation of the blood
  • Kidney or liver tumor that secretes the hormone erythropoietin
  • Inherited disease

Secondary polycythemia is managed primarily by treating the underlying condition causing the disorder. A patient with secondary polycythemia should have a return to normal red blood cell counts once the primary problem is successfully treated.

Medical History and Physical Examination

Evaluation of an individual with suspected PV should start with a detailed medical history and a physical examination by a hematologist-oncologist

The medical history should include information about the patient’s:

  • Cardiovascular risk factors
  • Past illnesses
  • Injuries
  • Treatments
  • Medications
  • A history of the formation or presence of a blood clot inside a blood vessel (thrombosis) or loss of blood from damaged blood vessels (hemorrhagic events)
  • History of blood relatives—some illnesses run in families
  • Current symptoms

After the medical history, the doctor will conduct a physical examination. During the physical examination, the doctor may:

  • Listen to the patient's heart and lungs
  • Examine the patient's body for signs of disease
  • Check different organs of the body

Blood Tests

Complete Blood Count

This test measures the number of red blood cells, white blood cells and platelets in a sample of blood. It also measures the amount of the iron-rich protein that carries oxygen in red blood cells and the percent of whole blood made up of red blood cells (the hematocrit). People with PV have high red blood cell counts. They also often have:

  • Increased white blood cells and platelets
  • Increased hemoglobin levels
  • Increased hematocrit levels

Red Cell Mast Test

This procedure is used to measure the volume (amount) of red blood cells in relation to the volume of plasma (fluid) in whole blood.

In patients with PV, there may be an absolute increase in red blood cell mass.

This test is infrequently performed in the United States due to high cost, difficulty obtaining the appropriate test materials, and the advent of new blood tests such as mutational testing.

Peripheral Blood Smear

A procedure in which a blood sample is viewed under a microscope. A pathologist examines the sample to see if there are any unusual changes in the size, shape and appearance of various blood cells. The test also checks for the presence of immature (blast) cells in the blood. 

Comprehensive Metabolic Panel

These tests measure the levels of substances released into the blood by organs and tissues. These include electrolyes, fats, proteins, glucose (sugar) and enzymes.

Blood chemistry tests provide important information about how well a person’s kidneys, liver and other organs are working. For patients suspected of having PV, it is important to test the serum erythropoietin level.

Erythropoietin is a hormone naturally produced by the kidneys to stimulate the production of new red blood cells. Individuals with PV usually have very low levels of erythropoietin. 

Bone Marrow Tests

Your doctor may examine your bone marrow even though the test isn't needed to diagnose PV.

Bone marrow testing involves two steps usually performed at the same time in a doctor's office or a hospital:

  • A bone marrow aspiration to remove a liquid marrow sample
  • A bone marrow biopsy to remove a small amount of bone filled with marrow

In PV, the bone marrow shows above-normal numbers of blood cells and an abnormal number of the platelet-forming cells called “megakaryocytes” in the bone marrow. The pathologist also examines the chromosomes of the bone marrow cells to rule out other blood diseases. 

Molecular Testing

Molecular genetic tests are very sensitive tests that look for specific gene mutations. If PV is suspected, molecular testing for the JAK2 mutation should be performed. The JAK2 V617F mutation is found in more than 90 percent of PV patients.

The U.S. Food and Drug Administration (FDA) has approved a test called ipsogen JAK2 RGQ PCR Kit to detect mutations affecting the Janus Tyrosine Kinase 2 (JAK2) gene. This test is intended to help doctors evaluate patients for suspected PV.

For more information about bone marrow tests and other lab tests, please see the free LLS publication Understanding Lab and Imaging Tests.

Criteria for Diagnosing Polycythemia Vera

In 2016, the World Health Organization published new criteria for diagnosing PV. The diagnosis of PV requires the presence of

  • Major Criteria 1, 2, and 3 (listed below) or
  • Major Criteria 1 and 2 and the minor criterion(listed below) 

Major Criteria 1.  Very high red blood cell count, usually identified by either A, B, or C below:

  • A. Hemoglobin level
    • Elevated levels of hemoglobin
      • Hemoglobin levels greater than 16.5 g/dL in men
      • Hemoglobin levels greater than 16.0 g/dL in women
  • B. Hematocrit level
    • Elevated levels of hematocrit
      • Hematocrit greater than 49 percent in men
      • Hematocrit greater than 48 percent in women
  • C. Red cell mass

Major Criteria 2. Bone marrow biopsy (A or B below) showing:

  • A. An abnormal excess of blood cells in the bone marrow (called “hyercellularity”) with an elevation of red blood cells, white blood cells and platelets (called “panmyelosis”)
  • B. Proliferation of mature megakaryocytes that vary in size and shape

Major Criteria 3. Presence of the JAK2V617F or JAK2 exon 12 gene mutation

Minor Criterion: Very low levels of erythropoietin

Source: https://www.lls.org/myeloproliferative-neoplasms/polycythemia-vera/diagnosis

Red Blood Cell Count – Understand Your Tests & Results

Possible Causes of High or Low Red Blood Cell Count

Sources Used in Current Review

Wintrobe's Clinical Hematology. 12th ed. Greer J, Foerster J, Rodgers G, Paraskevas F, Glader B, Arber D, Means R, eds. Philadelphia, PA: Lippincott Williams & Wilkins: 2009, Section 2: The Erythrocyte.

Harmening, D. Clinical Hematology and Fundamentals of Hemostasis, Fifth Edition, F.A. Davis Company, Philadelphia, 2009, Chapter 3.

Sources Used in Previous Reviews

Thomas, Clayton L., Editor (1997). Taber's Cyclopedic Medical Dictionary. F.A. Davis Company, Philadelphia, PA [18th Edition].

Pagana, Kathleen D. & Pagana, Timothy J. (2001). Mosby's Diagnostic and Laboratory Test Reference 5th Edition: Mosby, Inc., Saint Louis, MO.

Hillman RS and Finch CA. Red Cell Manual (1974). FA Davis, Philadelphia. Pp. 23-51.

Pagana, Kathleen D. & Pagana, Timothy J. (© 2007). Mosby's Diagnostic and Laboratory Test Reference 8th Edition: Mosby, Inc., Saint Louis, MO. Pp. 797-799.

Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. McPherson R, Pincus M, eds. Philadelphia, PA: Saunders Elsevier: 2007, Chap 31.

(March 1, 2011) National Heart, Lung and Blood Institute. What is Polycythemia vera? Available online at http://www.nhlbi.nih.gov/health/public/blood/index.htm. Accessed Sep 2011.

(Aug 1, 2010) National Heart, Lung and Blood Institute. Anemia. Available online at http://www.nhlbi.nih.gov/health/health-topics/topics/anemia/. Accessed Sep 2011.

(June 17, 2011) Conrad M. Anemia. Medscape Reference article. Available online at http://emedicine.medscape.com/article/198475-overview. Accessed Sep 2011.

(August 26, 2011) Harper J. Pediatric Megaloblastic Anemia. eMedicine article. Available online at http://emedicine.medscape.com/article/959918-overview. Accessed Sep 2011.

(June 8, 2011) Artz A. Anemia in Elderly Persons. eMedicine article. Available online at http://emedicine.medscape.com/article/1339998-overview. Accessed Sep 2011.

(February 9, 2010) Dugdale D. RBC Count. MedlinePlus Medical Encyclopedia. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003644.htm. Accessed Sep 2011.

Riley R, et.al. Automated Hematologic Evaluation. Medical College of Virginia, Virginia Commonwealth University. Available online at http://www.pathology.vcu.edu/education/PathLab/pages/hematopath/pbs.html#Anchor-Automated-47857. Accessed Sep 2011.

Kasper DL, Braunwald E, Fauci AS, Hauser SL, Longo DL, Jameson JL eds, (2005). Harrison's Principles of Internal Medicine, 16th Edition, McGraw Hill, Pp 329-336.

Pagana K, Pagana T. Mosby's Manual of Diagnostic and Laboratory Tests. 3rd Edition, St. Louis: Mosby Elsevier; 2006, Pp 447-448.

Harmening D. Clinical Hematology and Fundamentals of Hemostasis. Fifth Edition, F.A. Davis Company, Piladelphia, Chapter 3.

Maakaron, J. et. al. (Updated 2014 October 29). Anemia. Medscape Drugs & Diseases [On-line information]. Available online at http://emedicine.medscape.com/article/198475-overview. Accessed November 2014

Lehman, C. and Straseski, J. (Updated 2014 February). Anemia. ARUP Consult [On-line information]. Available online at http://www.arupconsult.com/Topics/Anemia.html?client_ID=LTD#tabs=0. Accessed November 2014

Gersten, T. (Updated 2014 February 24). RBC count. MedlinePlus Medical Encyclopedia [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003644.htm. Accessed November 2014

(2012 May 18). Anemia. National Heart Lung and Blood Institute [On-line information]. Available online at http://www.nhlbi.nih.gov/health/health-topics/topics/anemia/. Accessed November 2014

Kahsai, D. (Updated 2013 August 2). Acute Anemia. Medscape Drugs & Diseases [On-line information]. Available online at http://emedicine.medscape.com/article/780334-overview. Accessed November 2014

Curry, C. (Updated 2012 February 3). Erythrocyte Count (RBC). Medscape Drugs & Diseases [On-line information]. Available online at http://emedicine.medscape.com/article/2054474-overview. Accessed November 2014

Pagana, K. D., Pagana, T. J., and Pagana, T. N. (© 2015). Mosby's Diagnostic & Laboratory Test Reference 12th Edition: Mosby, Inc., Saint Louis, MO. Pp 785-791.

Source: https://labtestsonline.org/tests/red-blood-cell-count-rbc