What could cause 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 to 15 minutes of rest, the muscles go back to normal and I can continue for another mile or so. I am trying magnesium pills. Is there anything else you suggest?

A. I often suggest trying home remedies or exercise for many health issues, then calling your doctor if they don't work. But this is not one of those situations. Your symptoms could be caused by a serious condition. You need to contact your doctor.

You're right: mineral deficiencies — particularly not having enough magnesium, potassium, 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.

There are two fairly common, but potentially serious, conditions that can cause the kind of leg weakness you've described. The first is blockage of an artery that supplies blood to the leg muscles. Doctors call it peripheral artery disease. The second is spinal stenosis. In this condition, nerves that come out of the spinal cord are pinched by fragments of bone, thickened ligaments, or other forces.

But both peripheral artery disease and spinal stenosis usually cause leg pain. And you don't mention pain. People with diabetes are more likely to develop arterial blockage with little or no pain. So if you have diabetes, this is an even greater reason to see your doctor.

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