Anemia - Introduction

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Click the icon to see an image of the formed elements of blood.

Click the icon to see an image of hemoglobin.

Iron Deficiency Anemia

Iron deficiency anemia occurs when the body lacks mineral iron to produce the hemoglobin it needs to make red blood cells. In general, there are three stages leading from iron deficiency to anemia:

• First, there is an insufficient supply of iron, and iron stores are depleted in the bone marrow. This stage generally has no symptoms.
• Second, iron deficiencies develop and begin to affect hemoglobin production. (Tests, in such cases, reflect low hemoglobin and hematocrit levels.)
• Hemoglobin production declines to the point where anemia develops.

Most of the iron used in the body can be recycled from blood and reused. Nevertheless, iron deficiency can occur from a number of conditions.

Iron-Poor Diets. A healthy diet easily provides enough iron. In general, most people need just 1 mg, and menstruating women need 2 mg of extra iron each day. This means that lack of iron in the diet is not a common cause of iron deficiency anemia, except in infants. In fact, most American adults may be consuming too much iron in their diet. Most of the iron in red blood cells is recycled and reused. Iron-poor diets are a cause of anemia only in people with existing risks for iron deficiency.

Peptic Ulcers and Their Causes. The bacteria H. pylori are known to be primary causes of peptic ulcers, and many older people with ulcers have anemia. Anemia in such cases, however, may not result from bleeding ulcers. Instead, anemia is more likely due to the presence of bacteria impairing the ability of these people to absorb iron or vitamin B12. The bacteria, in fact, may also bind to iron and reduce its availability in the intestine, causing iron deficiency anemia.

Medications (NSAIDs). Aspirin and drugs such as ibuprofen and naproxen are called nonsteroidal anti-inflammatory drugs (NSAIDs). About 70% of long-term users of these medications have some sign of gastrointestinal bleeding, although it is rarely significant enough to cause anemia.