Most muscle cramps develop in the leg muscles, particularly in the calf. Besides the sudden, sharp pain, you might also 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
Overuse of a muscle, dehydration, muscle strain or simply holding a position for a prolonged period can cause a muscle cramp. In many cases, however, the cause 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 use 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 — also can deplete these minerals.
Factors that might increase your risk of muscle cramps include:
- Age. Older people lose muscle mass, so the remaining muscle can get overstressed more easily.
- Dehydration. Athletes who become fatigued and dehydrated while participating in warm-weather sports frequently develop muscle cramps.
- Pregnancy. Muscle cramps also are common during pregnancy.
- Medical conditions. You might be at higher risk of muscle cramps if you have diabetes, or nerve, liver or thyroid disorders.