ZocdocAnswersWhy does anemia cause fatigue?

Question

Why does anemia cause fatigue?

I have been fighting anemia on and off for years, and I usually have it under control. I take iron supplements and try to eat iron rich foods, but every one in a while I will have a debilitating bout of fatigue. Is this probably an effect of the anemia? How does it cause fatigue?

Answer

Anemia is a common medical problem that should be medically evaluated. The doctors who will be well qualified to discuss this issue with you include your internal medicine doctor. Anemia is simply defined as low levels of hemoglobin, which is the oxygen carrying chemical, in the blood stream. The mechanism by which anemia causes fatigue is quite simple. As the levels of hemoglobin fall, the ability of your blood to deliver oxygen to the brain, heart, muscles, and other tissues drops. This means less energy is available to these organs, and you perceive this as fatigue. Although it is possible that the fatigue you have been experiencing is simply from the anemia, it is also important to work out just why you have the chronic anemia. For example, if you have a source of chronic bleeding (such as an ulcer) this should be identified and fixed. There are also several general medical problems that could cause anemia as side effect, and these root causes might need to be treated. As always the diagnosis and the management of your particular concern will require a physical examination by your personal physician. Setting up an office visit with your internal medicine doctor is advised.

This answer is for general informational purposes only and is not a substitute for professional medical advice.

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