One of the classic signs of anemia is a feeling of overall weakness and fatigue that may seem to originate from the muscles.

Symptoms of anemia can be anything from mild to severe, and there’s quite a few potential symptoms.

The feeling of muscle weakness, or weak muscles, can arise from anemia. But “feeling” does not explain origin or cause.

A feeling of fatigue or tiredness is perhaps the most common sign of anemia.

If you feel this way, it’s easy to think that something is going awry with your muscles.

You may start believing that your muscles are weak – from the anemia that you either believe you have or were diagnosed with.

However, this feeling of fatigue and/or weakness has nothing to do with any inherent malfunction in your muscle fibers.

Your muscles are actually working fine, as far as innervation of the nerves that fire muscle contraction, and the components of muscle cells working to provide energy.

The problem is that, due to the anemia, your muscles don’t get enough oxygen.

Anemia means a deficiency in the number of red blood cells that get delivered to your muscles.

So think of it as a perfectly working car—engine, tires, etc., are all in good working order – but it sputters along the road because it doesn’t have enough fuel.

Also, in some cases of anemia the red blood cells contain less hemoglobin than they should.

So between an inadequate supply of red blood cells and an inadequate supply of hemoglobin, your muscles will be deprived of one of their fuel sources: oxygen.

Can Anemia Cause Muscle Wasting?

“Anemia is defined as reduction of red blood cells in the circulation, a condition brought about by many factors, most often by the loss of blood from any location,” says Morton Tavel, MD, Clinical Professor Emeritus of Medicine, Indiana University School of Medicine, and author of “Health Tips, Myths and Tricks: A Physician’s Advice.”

“When present, anemia most often results in fatigue and shortness of breath on exertion,” says Dr. Tavel.

“If present at all, muscular weakness is much less prevalent, and atrophy of muscles is thus not a feature of this disorder.

“Under any circumstance, however, since most forms of anemia are correctable, atrophy, which generally requires much time to develop, would not be expected before the anemia is corrected.”

Source: nhlbi.nih.gov/health/health-topics/topics/ida/signs anemia muscle weakness