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:

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
  • Abnormally low RBC production, due to:
  • Abnormally high RBC destruction, caused by inherited disorders such as:
    • Sickle cell anemia
    • Thalassemia —difficulty in manufacturing hemoglobin
    • Enzyme deficiencies