By the way, doctor: What is the cause of my sudden leg weakness?

Q. When I walk for about a mile, my leg muscles suddenly get very weak — so weak I can hardly walk. After 10–15 minutes of rest, the muscles go back to normal and I can continue for another mile or so. I am trying magnesium pills. Can you think of anything that might be causing this sudden weakness?

A. There are many problems for which I would suggest that you try a home remedy or a particular exercise and call your doctor only if they don't work. But this is not one of them. Your symptoms could be the result of several potentially serious conditions.

You're right: Mineral deficiencies, particularly shortages in magnesium and phosphate, can cause muscle weakness. But before you start treating yourself with magnesium or any other mineral, you should ask your doctor to check your levels. That can be done with a simple blood test.

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