Muscle Spasm - Muscle Cramp

A muscle cramp or "charley horse" is a painful, involuntary muscle contraction. Muscle cramps are also called muscle spasms.

What are the causes and risks of the condition?

The exact cause of muscle cramps is not well understood. They can occur in any muscle at any time. Cramps occur most often in the muscles of the leg or foot. They usually occur while playing sports, exercising, or lying in bed. The calf muscle in the back of the lower leg is a common place for nighttime cramps. These often occur after vigorous exercise.

Tight muscles are more likely to cramp than flexible muscles that have been stretched. A low level of physical fitness increases the risk of muscle cramps. Overexertion and muscle fatigue also contribute to cramping. Excess sweating or dehydration can deplete minerals in the body. These minerals are important for good muscle function and include sodium, potassium, calcium, magnesium, and phosphorus. Medications like diuretics or water pills can also lead to cramping due to loss of sodium and potassium.

Other situations can contribute to muscle cramping.

The common muscle cramp lasts a few seconds to minutes. It does not carry any risk of other long-term medical problems.

What are the signs and symptoms of the condition?

The main symptom of a muscle cramp or spasm is pain in the muscle. The muscle itself is tender to the touch. In most cases a person is unable to continue using the affected muscle due to the pain.

How is the condition diagnosed?

Common muscle cramps are easily recognized. They cause intense pain in the belly of the muscle. The pain may come on while exercising or at rest. It usually lasts seconds to minutes. The pain of claudication in the calf or buttucks comes on during physical activity, like walking up a hill, and goes away with rest.

What can be done to prevent the condition?

Stretching the calf and other leg muscles improves flexibility. This reduces the risk of cramps. Individuals who get nighttime calf cramps should:

In the past, salt tablets were recommended to prevent muscle cramps. However, salt tablets are not useful and should be avoided.

What are the treatments for the condition?

The immediate treatment of a charley horse or muscle cramp is to stretch and gently massage the muscle. To stop a calf cramp:

If one has been exercising or playing sports for a long time, especially in hot weather, loss of minerals may cause muscle cramps. A sports drink may be helpful. Salt tablets should be avoided. Quinine may help reduce nighttime calf cramps, but its use should be discussed with a doctor.

What are the side effects of the treatments?

Most of the various treatments do not have side effects. Quinine can sometimes cause ringing in the ears, hearing problems, stomach upset and rarely more serious side effects, such as heart problems and deafness.

What happens after treatment for the condition?

Once the cramping has stopped, an individual is usually able to continue regular activities. If severe muscle cramping occurs repeatedly, the individual should see a doctor for evaluation.

Author:Minot Cleveland, MD
Date Written:
Editor:Evans, Gwen, BA
Edit Date:03/15/00
Reviewer:Adam Brochert, MD
Date Reviewed:09/19/01