Muscle cramps

DEFINITION

A muscle cramp is a sudden and involuntary contraction of one or more of your muscles. If you’ve ever been awakened in the night or stopped in your tracks by a sudden charley horse, you know that muscle cramps can cause excruciating pain. Though generally harmless, muscle cramps can make it temporarily impossible to use the affected muscle.

Long periods of exercise or physical labor, particularly in hot weather, may lead to muscle cramps. Some medications and certain medical conditions also may cause muscle cramps. You can usually treat muscle cramps at home with self-care measures.

CAUSES

Overuse of a muscle, dehydration, muscle strain or simply holding a position for a prolonged period of time may result in a muscle cramp. In many cases, however, the exact cause of a muscle cramp isn’t known.

Although most muscle cramps are harmless, some may be related to an underlying medical condition, such as:

• Inadequate blood supply. Narrowing of the arteries that deliver blood to your legs (arteriosclerosis of the extremities) can produce cramp-like pain in your legs and feet while you’re exercising. These cramps usually go away soon after you stop exercising.
• Nerve compression. 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 employ when pushing a shopping cart ahead of you — may improve or delay the onset of your symptoms.
• Mineral depletion. Too little potassium, calcium or magnesium in your diet can contribute to leg cramps. Diuretics — medications often prescribed for high blood pressure — may also deplete these minerals.

SYMPTOMS

Most muscle cramps develop in the leg muscles, particularly the muscles in the calf. In addition to the sudden, sharp pain, you may also be able to feel or see a hard lump of muscle tissue beneath your skin.

When to see a doctor

Muscle cramps usually disappear on their own and are rarely serious enough to require medical care. However, see your doctor if your cramps:

• Cause severe discomfort
• Are associated with leg swelling, redness or skin changes
• Are associated with muscle weakness
• Happen frequently
• Don’t improve with self-care
• Aren’t associated with an obvious cause, such as strenuous exercise