What are Leg Spasms?

Leg spasms occur when a muscle in the leg, usually the calf, suddenly tightens involuntarily, causing a sensation sometimes called a charley horse. They can be painful and momentarily debilitating, but usually resolve on their own with little or no treatment. Sometimes spasms can be the result of improper exercise, a dietary deficiency, or dehydration. Cramps and spasms also can be caused by medication side effects or an underlying medical condition, but many have no discernible cause.

Leg spasms can result from the overuse or repetitive use of a muscle, such as while bicycling or doing squat exercises. Drinking too little water during or after exercise can also cause leg cramps, especially when running or jogging on a hot day. A lack of magnesium, potassium, or calcium can also trigger cramps, and medications that deplete potassium levels, such as high blood pressure prescriptions, can cause spasms.

Painful leg cramps and spasms have a variety of medically-related causes as well. For example, spinal stenosis, a compression of the spinal cord, can cause leg spasms due to inadequate nerve conduction. Another spinal condition called sciatica compresses the large sciatic nerve that runs from the spine down the leg, which can cause a charley horse in the calf and cause spasms. Certain neurological disorders, such as Multiple sclerosis, cerebral palsy, and muscular dystrophy, can also cause leg spasms and uncontrollable twitching. Reduced blood flow to the legs, often cause by arteriosclerosis, can cause leg pain while walking. Other medical conditions that can contribute to spasms include anemia, diabetes, hypothyroidism, and hypoglycemia.

Though a physician may prescribe a muscle relaxant if leg spasms are regularly disturbing a person’s sleep, stretching and applying heat and cold are the most frequently recommended treatments for alleviating leg cramps. For example, during a calf spasm, stretching the leg out and pulling the toe toward the head will stretch the cramped muscle and help eliminate the spasm. Massage can also assist the muscle in relaxing the contraction. Applying a heating pad to the affected area, followed by an ice pack, can reduce leg pain as well.

Prevention generally is the key to eliminating leg spasms provoked by exercise. Fitness experts often recommend stretching before exercising to warm up the muscles. It also is recommended to drink plenty of water before, during, and after intense exercise. For spasms due to spinal stenosis or sciatica, walking slightly bent over to relieve the stress on the spinal cord or sciatic nerve may provide some relief. Stretching before going to bed may help prevent leg cramps during sleep.