In general, anemia is caused by one of the following:
- An inability of the body to make red blood cells
- Premature destruction of the red blood cells
- Bleeding, or loss of red blood cells
Blood loss from repeated severe nosebleeds, heavy menstrual periods, a bleeding stomach ulcer or certain intestinal disorders can cause anemia. When there are insufficient amounts of important vitamins and other substances that are crucial for the production of new red cells, anemia may occur.
Inherited defects of enzymes, cell membrane structure, or hemoglobin molecules inside the cell may cause red cells to be more fragile and prone to premature destruction. Problems in the bone marrow where red blood cells are produced can also cause anemia. This can be a mild anemia that may occur in conjunction with a viral illness or a more severe anemia because the function of the marrow has been nearly destroyed, which can be due to hepatitis, toxins or, rarely, leukemia.
Finally, children who have serious chronic illnesses may have anemia due to the condition itself or medication used to treat it.
A common form of anemia in childhood is due to iron deficiency. Iron is an essential component of the molecules inside red blood cells that carry oxygen. Iron is also important for some enzymes systems in the body and for the normal function of certain organs such as the brain.
There are many causes of iron deficiency anemia, depending upon the age of child and whether there are other medical problems. Iron deficiency anemia is most often due to inadequate iron intake in the diet.