Saturday, February, 11, 2012

Anemia - Risk Factors

Table of Contents

Causes


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, which causes iron stores in the bone marrow to be depleted. This stage generally has no symptoms.
  • Second, iron deficiencies develop and begin to affect hemoglobin production. (Tests will show 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.

Inadequate Iron Intake. 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. Iron-poor diets are a cause of anemia only in people with existing risks for iron deficiency. Children who have not yet eaten iron-fortified formulas or iron-enriched cereal may also become anemic.

Blood Loss. Iron deficiencies most commonly occur from internal blood loss due to other conditions that vary in severity. These conditions include:

  • Very heavy periods (menorrhagia), the most common causes of anemia in menstruating women
  • Peptic ulcers, which may be caused by H. pylori infections, or use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen, and naproxen.
  • Chronic gastritis, caused by long-term use of NSAIDs, although it is rarely significant enough to cause anemia.
  • Duodenal ulcers
  • Hemorrhoids, though rare
  • Colon polyps
  • Colon, stomach, and esophageal cancer
  • Bleeding from esophageal varices, often present in alcoholics

Review Date: 01/13/2011
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)