Anemia
Condition
Definition
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.
Anemia may be:
- Iron-deficiency anemia—the body does not have the levels of iron needed to make RBCs
- Vitamin B12 deficient anemia and pernicious anemia—low levels of a vitamin that is needed to make RBCs
- Anemia of inflammation—happens with long term health issues
- Aplastic anemia—bone marrow cannot make enough RBCs
- Sickle cell anemia—RBCs have an abnormal shape and do not work well
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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
- Body does not make enough RBCs. This can happen because of:
- 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 women and those who are pregnant. It is also more common in older adults who are sick or infants less than 2 years of age.
Other things that may raise the risk of anemia include:
- A diet that is low in iron, vitamins, and minerals
- Blood loss that 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
Symptoms
Anemia may cause:
- Tiredness
- Paleness
- Shortness of breath
- Lightheadedness
- Headache
- Coldness in the hands and feet
- Chest pain
- Rapid or irregular heartbeat
Diagnosis
The doctor will ask about symptoms and health history. A physical exam will be done. Blood tests will measure RBC counts, hemoglobin, and other parts of the blood. Other tests may be needed to look for causes.
Treatment
The goal of treatment is to increase healthy RBCs. How this is done depends on what is causing the anemia. Treating the underlying cause may help. Other steps that may help increase RBCs include:
- Some vitamins and minerals are needed to make red blood cells. Eating foods that are 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 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 grow new healthy bone marrow. This new marrow should be able to make healthy RBCs. This procedure carries risk. It is only done when the anemia is very bad.
Prevention
A diet rich in iron and vitamins may help prevent some types of anemia.
Iron Disorders Institute
National Heart, Lung, and Blood Institute
CANADIAN RESOURCES:
Canadian Blood Services
Health Canada
Iron Disorders Institute
National Heart, Lung, and Blood Institute
CANADIAN RESOURCES:
Canadian Blood Services
Health Canada
References
- Anemia in adults - approach to the patient. EBSCO DynaMed website. Available at: https://www.dynamed.com/approach-to/anemia-in-adults-approach-to-the-patient.
- Anemia of inflammation. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/anemia-of-inflammation.
- Iron deficiency anemia in adults. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/iron-deficiency-anemia-in-adults.
- Vieth, J.T. and Lane, D.R. Anemia. Hematol Oncol Clin North Am, 2017; 31 (6): 1045-1060.
- What is anemia? National Heart, Lung, and Blood Institute website. Available at: https://www.nhlbi.nih.gov/health/anemia.
Contributors
- Marcin Chwistek, MD
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