Muscle cramps are sudden, involuntary contractions or spasms in one or more of your muscles. They are very common and often occur after exercise. Some people get muscle cramps, especially leg cramps, at night. They can be painful, and they may last a few seconds to several minutes.

You can have a cramp in any muscle, but they happen most often in the:

• Thighs
• Feet
• Hands
• Arms
• Abdomen
• Area along your ribcage

Anyone can get muscle cramps, but they are more common in some people:

• The elderly
• People who are overweight
• Athletes
• Pregnant women
• People with certain medical conditions, such as thyroid and nerve disorders

Causes of muscle cramps include:

• Straining or overusing a muscle. This is the most common cause.
• Compression of your nerves, from problems such as a spinal cord injury or a pinched nerve in the neck or back
• Dehydration
• Low levels of electrolytes such as magnesium, potassium, or calcium
• Not enough blood getting to your muscles
• Pregnancy
• Certain medicines
• Getting dialysis

Sometimes the cause is not known.

Muscle cramps are usually harmless, and they go away after a few minutes. But you should contact your health care provider if the cramps

• Are severe
• Happen frequently
• Don't get better with stretching and drinking enough fluids
• Last a long time
• Are accompanied by swelling, redness, or a feeling of warmth
• Are accompanied by muscle weakness

You usually don't need treatment for muscle cramps. You may be able to find some relief from cramps by

• Stretching or gently massaging the muscle
• Applying heat when the muscle is tight and ice when the muscle is sore
• Getting more fluids if you are dehydrated

If another medical problem is causing the cramps, treating that problem will likely help. There are medicines that providers sometimes prescribe to prevent cramps, but they are not always effective and may cause side effects. Talk to your provider about the risks and benefits of medicines.

To prevent muscle cramps, you can:

• Stretch your muscles, especially before exercising. If you often get leg cramps at night, stretch your leg muscles before bed.
• Drink plenty of liquids. If you do intense exercise or exercise in the heat, sports drinks can help you replace electrolytes.