Overuse of a muscle, dehydration, muscle strain or simply holding a position for a prolonged period can cause muscle cramp. In many cases, however, the cause isn’t known.
Most muscle cramps are harmless, some may be related to an underlying medical condition, such as inadequate blood supply due to narrowing of the arteries that deliver blood to your legs. These cramps usually go away soon after you stop exercising.
Compression of nerves in your spine (lumbar stenosis) also can produce cramp-like pain in your legs. The pain usually worsens the longer you walk. Walking in a slightly flexed position — such as you would use when pushing a shopping cart ahead of you — may improve or delay the onset of your symptoms.
Muscle cramps also are common during pregnancy and you might be at higher risk if you have diabetes, or nerve, liver or thyroid disorders.
Avoid dehydration. Drink plenty of liquids every day. The amount depends on what you eat, your sex, your level of activity, the weather, your health, your age and medications you take.
Fluids help your muscles contract and relax and keep muscle cells hydrated and less irritable. During activity, replenish fluids at regular intervals, and continue drinking water or other fluids after you’re finished.
Stretch your muscles. Stretch before and after you use any muscle for an extended period. If you tend to have leg cramps at night, stretch before bedtime. Light exercise, such as riding a stationary bicycle for a few minutes before bedtime, also may help prevent cramps while you’re sleeping.