Blood Will Tell
By Rear Adm. Joyce Johnson, D.O., M.A.

What is anemia? Should I take iron to prevent it?

Red blood cells transport oxygen to other cells, where it chemically releases energy. Anemia due to abnormalities in red blood cells is common in older adults—about one third of those seen as outpatients have had it. It can be the result of blood loss, improper red blood cell development, or excessive destruction of red blood cells.

Blood loss, whether it is acute (fast and sudden) or chronic (slowly over time), is a common cause of anemia. For example, a stomach ulcer might “ooze” over many months or cause a sudden, massive, life-threatening bleed; in either case, loss of blood can lead to anemia. Women beginning menopause, especially if they have bleeding uterine fibroids, might have excessive menstrual bleeding, which also can lead to anemia. Reducing blood loss by treating the underlying cause will cure the anemia.

The body constantly makes red blood cells, which live for about four months. Impaired production can result in an inadequate number of cells or cells that are too small or too large. Impairment might be the result of kidney disease (the kidneys produce erythropoietin, which is needed for blood cell development) or caused by medications, such as some cancer treatments that “poison” the blood-producing system. Iron deficiency causes blood cells that are too small; a vitamin B-12 deficiency (perhaps from an inability to absorb dietary vitamin B-12) results in red blood cells that are too large and are not efficient in oxygen transfer (known as pernicious anemia). These deficiencies can be treated with iron supplements and injections of vitamin B-12, respectively.

Hemolysis is the body’s process of destroying worn-out red blood cells to recycle the iron in them. When the rate of hemolysis exceeds the rate of red-blood-cell production, anemia can result. Sickle-cell disease is a hemolytic anemia. Rather than being spherical, the red blood cell is shaped like a sickle. These sickle-shaped cells get caught in the vascular system during circulation, damaging the cell and causing increased hemolysis. 

Many symptoms of anemia, such as shortness of breath, weakness, lethargy, and dizziness, are related to inadequate oxygen transport. A common lab test, the complete blood count (CBC), gives the number and size of red cells. When anemia is identified, management involves recognizing and addressing the underlying disease. A CBC coupled with a complete patient medical history can help a doctor determine the cause. Anemia can be a sign of serious disease; luckily, the cause often is easy to treat.