Although anemia seems like a disease, it’s really a symptom of something else that is causing a decrease in the number of red blood cells. In other words, anemia is typically a symptom of another condition.

The Role of Blood Cells

There are many types of blood cells, and each has a job to do. White blood cells, for instance, fight infection. Platelets allow blood to clot, and red blood cells carry hemoglobin—a protein that is rich in iron. It is what gives the cells their color.

Hemoglobin importantly allows the blood to carry oxygen molecules to cells. Specifically, when a person inhales, the lungs collect oxygen molecules from the air. Red blood cells pick up the oxygen molecules from the lungs, then travel to the cells to deliver it. After dropping off the oxygen, they pick up carbon dioxide on the way back to the lungs, and it is exhaled. When there are not enough red blood cells, cells do not get oxygen, and they retain carbon dioxide. This condition is known as anemia.

Types of Anemia

There are different kinds of anemia, each with a specific cause.

Iron Deficiency

Iron deficiency anemia means that the body doesn’t have enough iron to make an adequate amount of hemoglobin.

Vitamin Deficiency

Vitamin deficiency anemia indicates a lack of sufficient folate and vitamin B12 (cobalamin), also necessary elements for red blood cell production.


Anemia of inflammation can be a side effect of certain diseases such as cancer, AIDS, rheumatoid arthritis, kidney disease, and chronic inflammatory diseases such as Crohn’s.

Bone Marrow Aplasia

aplastic anemia. disease bone marrow

Aplastic anemia, or bone marrow aplasia, is a rare condition that keeps the body from making red blood cells. It is potentially fatal.

Other Bone Marrow Diseases

Normal red blood cells vs blood appearance with leukemia
decade3d – anatomy online/Shutterstock.com

Bone marrow manufactures red blood cells, so diseases that affect it will also lead to anemia.  For example, leukemia is a type of cancer that affects the blood.


Hemolysis. Normal red blood cell, spherocyte, and rupturing of erythrocyte (release of contents into blood plasma). Vector illustration for medical use

Hemolytic anemia means the body is destroying red blood cells faster than it is making them, leading to a deficiency. 

Sickle Cell Disease

anemia. sickle cell and normal red blood cell

Finally, sickle cell anemia (sickle cell disease) is an inherited illness seen mostly in the United States among African Americans. This condition leads to a defect in the hemoglobin; specifically, the red blood cells take on an unusual shape that many liken to a sickle. As a result of this abnormal shape, they often die while still premature. It therefore deprives the cells of oxygen because there is a chronic shortage of red blood cells. Furthermore, sometimes these abnormally shaped cells can get stuck in smaller blood vessels and reduce or even stop blood flow.

Causes and Risk Factors

Risk factors of the various forms of anemia include:

  • Poor nutrition – The diet lacks certain vitamins and minerals specifically iron, folate, and vitamin C (ascorbic acid)
  • B12 intestinal disorders – Certain intestinal problems affect the absorption of these important nutrients 
  • Heavy menstruation – It’s not uncommon for cisgender women to become anemic during their periods
  • Pregnancy – The risk of anemia is one reason healthcare providers recommend prenatal vitamins for those expecting a baby
  • Chronic medical conditions – Everything from a bleeding ulcer to diabetes can affect red blood production and iron usage
  • Genetics – Some forms of anemia can run in families, such as sickle cell
  • Age – People over the age of 65 are prone to anemia


What causes a person to become anemic?

There are three main causes of anemia:

  1. blood loss,
  2. low production of red blood cells, or
  3. increased destruction of them.

A person bleeding can become anemic due to blood loss. So can someone with the condition that affects red blood cell production such as leukemia or one that causes premature destruction of the cells like sickle cell disease.

Can anemia kill you?

There are varieties that can be fatal, such as aplastic anemia. Most of the time, anemia is itself a symptom of another condition, some of which are potentially fatal, such as blood loss or cancer. 

How do you fix anemia?

The goal of treatment is to fix whatever is causing the anemia, so red blood cell population increases. For the most common type of anemia, iron deficiency, the treatment is to take supplemental iron until these levels return to normal. If the deficiency is due to bleeding, it’s necessary to locate and stop it. For vitamin deficiencies, eating foods high in iron and B12 can help as can nutritional supplements. 

Disclaimer: this article does not constitute or replace medical advice. If you have an emergency or a serious medical question, please contact a medical professional or call 911 immediately. To see our full medical disclaimer, visit our Terms of Use page.

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