by McCoy K


Anemia is a low level of healthy red blood cells (RBCs). RBCs carry oxygen from the lungs to the rest of the body. When red blood cells are low, the body does not get enough oxygen.

There are several specific types of anemia, including:

Red Blood Cells
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The main causes of anemia are:

  • Blood loss, such as that caused by:
    • Heavy menstrual periods
    • Bleeding in the digestive tract
    • Bleeding in the urinary tract
    • Surgery
    • Trauma
    • Cancer
  • Body does not make enough RBCs due to one of the following:
    • Kidney disease
    • Cancer
    • Infection
    • Medication
    • Radiation therapy
    • Pregnancy
    • Lead intoxication
  • RBCs are destroyed at a higher rate than normal because of health issues such as:
    • Sickle cell anemia
    • Thalassemia
    • Low levels of certain enzymes

Risk Factors

Anemia is more common in woman and those who are pregnant. It is also more common in older adults who are sick or infants less than 2 years old.

Other factors that may increase the risk of anemia include:

  • Poor diet which is low in iron, vitamins, and minerals
  • Blood loss which may be due to periods, surgery, or injury
  • Chronic or serious illness
  • Chronic infections
  • Family history of inherited anemia such as sickle cell anemia and thalassemia


Anemia may cause:

  • Tiredness
  • Paleness
  • Shortness of breath
  • Lightheadedness
  • Headache
  • Coldness in the hands and feet
  • Chest pain
  • Rapid or irregular heartbeat


You will be asked about your symptoms and past health. A physical exam will be done. Blood tests will show how many RBCs there are and if they are healthy. Other tests may be needed to look for causes.


The goal of treatment is to increase healthy RBCs. The exact steps will depend on the cause. Treating the underlying cause may relieve some anemia. Other steps that may help to increase RBCs include:

  • Certain vitamins and minerals are needed to make red blood cells. Foods rich in iron, vitamin C, vitamin B12, and folate can help. Some people may need supplements if they can not get enough nutrients from food.
  • Medicine may help to increase the amount of RBCs the body can make.
  • A blood transfusion can quickly increase RBCs. The effect will not last if the cause of anemia is not treated.
  • RBCs are made in the bone marrow. Transplanting bone marrow or stem cells can help to grow new healthy bone marrow. This new marrow should be able to make healthy RBCs. This procedure carries risk. It is only done in severe cases of anemia.


A diet rich in iron and vitamins may help to prevent some types of anemia.


Iron Disorders Institute 

National Heart, Lung, and Blood Institute 


Canadian Blood Services 

Health Canada 


Anemia in Adults - Approach to the Patient. EBSCO DynaMed website. Available at: Accessed February 7, 2021.

Anemia of Inflammation. EBSCO DynaMed website. Available at: Accessed February 7, 2021.

Explore anemia. National Heart, Lung, and Blood Institute website. Available at: Accessed February 7, 2021.

Iron Deficiency Anemia in Adults. EBSCO DynaMed website. Available at: Accessed February 7, 2021.

Vieth JT, Lane DR. Anemia. Hematol Oncol Clin North Am. 2017 Dec;31(6):1045-1060.

Revision Information

  • Reviewer: EBSCO Medical Review Board Marcin Chwistek, MD
  • Review Date: 02/2021
  • Update Date: 02/21/2021