Glossary
Anemia: A below-normal level of hemoglobin or hematocrit; below 36% for women, below 39% for men.

Erythropoietin: The hormone that regulates red blood cell production.

Erythropoiesis-stimulating agents (ESAs): A man-made drug which stimulates red blood cell production by mimicking the body's natural erythropoietin.

Inflammation: Your body's response to injury or irritation; often associated with pain, redness, heat, and/or swelling.

Hematocrit: The percentage of red blood cells in a blood sample.

Hemoglobin: A protein carried by red blood cells that transports and delivers oxygen throughout the body.

Rheumatoid arthritis: A chronic inflammatory disease of the joints and connective tissues.

Causes for Deferral

Chronic Illnesses

Donating blood is a great way to help your community, but sometimes you can be turned down from donating because your blood count is too low. This is called being "deferred" and about 10% of people who attempt to donate are deferred because of a low blood count.1 Don't feel bad if you were deferred for this reason because it is one of the most common reasons people are not allowed to donate blood.2 After testing a sample of your blood, you may have been told your "iron is low", you have a "low blood count", "low hemoglobin" or "low hematocrit." Essentially, each of these terms means you do not have enough red blood cells in your body to donate blood.

The medical term for a lower than normal blood count is anemia and there are many reasons why it can develop. One cause may be that a chronic illness such as arthritis, diabetes or kidney disease is stopping your body from making enough healthy red blood cells. Even though you were not allowed to donate on a particular day due to low blood count, there are usually steps you can take to treat anemia and raise your blood count. Then you can return and try to donate again.

What is a chronic illness and which ones can cause a low blood count?

A chronic illness is an illness that is long-lasting or recurrent and usually requires long-term therapy. Chronic illnesses often lead to lower blood counts and are probably the most common cause of anemia in older adults.25 Some chronic illnesses that can cause a low blood count include arthritis, diabetes, heart disease, HIV/AIDS, inflammatory bowel disease or kidney disease. People often know they have these conditions before they donate blood and are taking steps to treat or manage the illness. You should be under the care of a doctor if you have one of these conditions.

How do chronic illnesses cause a low blood count?

Chronic illnesses can cause a low blood count through a variety of ways which relate to how your body maintains healthy blood. The illness may prevent the normal production of healthy red blood cells either by not having enough of the protein called erythropoietin or by not supplying enough of the blood components, like iron.19 In many cases, your body's response to the illness, called inflammation, can stop iron from playing its normal role in making new red blood cells.

Chronic illnesses may also destroy red blood cells or possibly cause bleeding. In each case, the body has fewer red blood cells resulting in a lower blood count and potentially anemia.

How can I tell if my low blood count is caused by a chronic illness?

Sometimes a low blood count can be a sign of having a chronic illness. If you have a low blood count but have not been diagnosed with a chronic illness, you may want to check with your doctor to rule out that possibility. If you already know you have a chronic illness, you are most likely seeing your doctor on a regular basis. If you find out you have a low blood count, you may want to discuss this and any additional symptoms you may be experiencing with your doctor during these visits to see if they are linked to your chronic illness. Sometimes there might not be any signs, but as anemia gets worse, you may start to notice some symptoms like fatigue, weakness, pale skin, chest pain, dizziness, irritability, numbness or coldness in your hands and feet, trouble breathing, a fast heartbeat, and headache.19 If you are experiencing any of these symptoms you may want to mention it to your doctor.

General Healthy Hematocrit
and Hemoglobin Values
  Female Male
Hemoglobin 12.3 - 15.3 g/dL 14.0 - 17.4 g/dL
Hematocrit 36.0 - 45.0% 41.5 - 50.4%
Reference ranges for illustrative purposes only and may vary by age, ethnic group and pre/postmenopausal females. Perkins S. Wintrobe's Clinical Hematology. 1998.22

The best way to determine if you have anemia due to a chronic illness is to discuss your blood count with your doctor. Your doctor can determine if you are anemic by performing a routine blood test called a complete blood count (CBC) test, which provides levels for both hemoglobin and hematocrit. The measurement of hemoglobin is the most common method for assessing anemia, although hematocrit values may also be used. The healthy blood count range depends on both gender and age.


If my low blood count is caused by a chronic illness, how can I treat it?

It is important to talk with your doctor about changes in your health - to understand which problems can be treated and to discuss your treatment options. If the underlying chronic illness can be effectively treated, the anemia often improves. If your body is low in stored iron or vitamins, it is important to treat these deficiencies first. Drugs that stimulate red blood cell production, called erythropoietin-stimulating agents (ESAs), are sometimes used to raise blood counts.

Close communication with your doctor will help him or her provide the treatment that is best for you based on what is causing the anemia. For more information on anemia of chronic disease, read our patient information handouts which provide details about anemia specific to each chronic disease.

How can I prevent becoming anemic as a result of my chronic illness?

Anemia is a common complication of chronic illnesses, so your doctor may already be monitoring your blood count. Close communication with your doctor about your medications, symptoms, and low blood count during donation will help him or her determine the best plan of action to prevent anemia. Additionally, it is important to eat a healthy, balanced diet and take any vitamins, multivitamins or supplements as directed by your doctor to prevent anemia caused by iron or vitamin deficiencies.

Deciding on a treatment and prevention plan with your doctor and strictly following these recommendations, you may be healthy enough to donate blood once again.