Definition

Anemia is a low level of healthy red blood cells (RBC). 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:

• Anemia of chronic disease —chronic diseases can slow the production of RBCs
• Aplastic anemia —bone marrow is not able to produce enough RBCs
• Iron-deficiency anemia —iron is a building block of hemoglobin
• Macrocytic B12 deficient anemia and pernicious anemia —B12 is a building block of RBCs
• Sickle cell anemia —RBCs have an abnormal shape that causes destruction of RBCs and low levels of hemoglobin

Causes

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
• Abnormally low RBC production, due to:
  • Kidney disease
  • Cancer
  • Infection
  • Medication
  • Radiation
  • Pregnancy
  • Lead intoxication
• Abnormally high RBC destruction, caused by inherited disorders such as:
  • Sickle cell anemia
  • Thalassemia —difficulty in manufacturing hemoglobin
  • Enzyme deficiencies

Risk Factors

Anemia is more common in:

• Women of childbearing age
• Women who are pregnant
• Older adults with other medical conditions
• Infants younger than two years of age

Factors that may increase your chances of anemia include:

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

Symptoms

Symptoms of anemia may include:

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

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done.

Your bodily fluids and tissues may be tested. This can be done with:

• Blood tests
• Stool tests
• Bone marrow aspiration or biopsy

Treatment

Talk with your doctor about the best plan for you. Options include:

Prevention

Most inherited forms of anemia cannot be prevented. But the following steps may be taken to prevent certain types of anemia:

• Eat a diet rich in iron and vitamins.
• Take iron or vitamin supplements, as advised by your doctor.
• Treat underlying causes of anemia.
• Report signs and symptoms, especially chronic fatigue, to your doctor.

National Heart, Lung, and Blood Institute http://www.nhlbi.nih.gov

Health Canada http://www.hc-sc.gc.ca

Guralnik JM, Eisenstaedt RS, Ferrucci L, Klein HG, Woodman RC. Prevalence of anemia in persons 65 years and older in the United States: evidence for a high rate of unexplained anemia. Blood. 2004;104:2263-2268.

Nissenson AR, Goodnough LT, Dubois RW. Anemia: not just an innocent bystander? Arch Intern Med. 2003;163:1400-1404.

What is anemia? National Heart, Lung, and Blood Institute website. Available at:
http://www.nhlbi.nih.gov/health/dci/Diseases/anemia/anemia_whatis.html
Updated May 18, 2012. Accessed November 1, 2012.