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 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.

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