Leg Cramp
When a muscle involuntarily contracts, we call this a spasm. If this spasm is forceful, it is considered a cramp. This means that a muscle cramp is a forcibly and involuntarily contracted muscle that will not relax. These muscle cramps can last for a few seconds or even fifteen minutes. On rare occasions, the cramps can last longer than this. Some cramps involve the contraction of muscles that normally move your body parts in the opposite direction, and they are cramping at the same time.
Cramps are common. Nearly everyone experiences cramps at some point in their lives. Even children sometimes experience cramps, but cramps typically become more frequent as we age. Any muscles that we control voluntarily can cramp. Cramps of the extremities are most common, particularly cramps of the calf, such as a “charley horse.”
There are several types of cramps. They are classified into four groups: true cramps, tetany, contractures, and dystonic cramps.
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True cramps involve the entire muscle or group of muscles that act together. This is the most common type of skeletal muscle cramps. They are caused by several factors. Injury cramps are persistent muscle spasms that act as protective mechanisms after an injury. The spasm tends to control the movement and acts to stabilize the area of the injury. The injury of the muscle causes the muscles to spasm. Vigorous activity cramps are associated with fatigue of the muscle. These cramps may come while the activity is in session or even hours later after the activity was completed. Fatigue of the muscle may occur after sitting or lying for a period of time or if you are in an awkward position. If you have a lot of repetitive use of a muscle, a cramp can also begin. Older people are particularly at risk for cramps when they are involved in strenuous or vigorous physical activity. Rest cramps are common, particularly in older adults. These cramps often happen during the night hours and can be painful and also disrupt you
r sleep. They can recur often. The cause of these cramps is unknown, but they may be caused by making a movement that shortens the muscle, such as pointing the toe down while you are lying down. This acts to shorten the calf muscle, which is a common location of cramps. Dehydration can also be a cause of true cramps. These cramps are most likely to occur in warm weather. They also can be a sign of impending heat stroke if you do not get out of the sun and get some liquids into your body. Additionally depletion of body fluids through the use of diuretics can predispose a person to cramps. Depletion of sodium has also been associated with true cramps from dehydration. Body fluid shifts can also be a cause, such as in cirrhosis of the liver or hemodialysis. If you have low blood levels of either magnesium or calcium, you may increase the excitability of the nerve endings and muscles. This may occur in pregnancy unless these minerals are being supplemented through diet or vitamins. Low potassium levels also sometimes cause muscle cramps, yet it is more common for low potassium to be related to muscle weakness.
- Tetany occurs when all of the nerve cells in the body become activated, which stimulates the muscles. This causes spasms or cramps to occur throughout your body. This muscle cramping can be the result of low blood levels of calcium and magnesium. Also these cramps are often related to hyperactivity of the nerve functions in addition to the muscle stimulation.
- Contractures are a result of the muscles being unable to relax. The spasms are caused by a depletion of ATP, or adenosine triphosphate, which is an energy chemical in the cell. This keeps muscle fiber relaxation from happening. The nerves are actually inactive in this type of muscle spasm. Sometimes contractures are inherited or acquired. McArdie’s disease is a defect of the breakdown of glycogen to sugar that is within the muscle cell. Hyperthyroid myopathy is a muscle disease associated with an overactive thyroid. All in all, contractures are an uncommon type of cramp.
- Dystonic cramps are cramps in which the muscles that are not needed for the movement are stimulated and as a result, contract. The muscles that are affected by this type of cramping are the ones that normally work in the opposite direction of the movement that is intended. Some dystonic cramps will affect the smaller groups of muscles, such as the jaws, neck, larynx, or eyelids. This type of cramp is also not as common as true cramps.
Causes of Muscle Cramps
There are several causes of muscle cramps. One cause is an overuse of a particular muscle. Diuretic medications have been known to cause cramps because they lower body fluid and sodium. They also are responsible for the loss of calcium, potassium, and magnesium, which all can cause cramps. Cramps are also common for people who are experiencing withdrawal from medications and substances, such as barbiturates, alcohol, anti-anxiety agents, narcotics, and other sedatives and drugs. Vitamin deficiencies can also result in muscle cramps, such as the deficiencies of thiamine, pyridoxine, and pantothenic acid.
Symptoms of Muscle Cramps
Typically a cramp is very painful. If you are experiencing a cramp, you probably have to stop whatever you are doing in order to seek relief from the pain of the cramp. Cramps can also be associated with soreness and swelling. This can sometimes persist for up to several days after the cramp is over. Typically the cramp will be knotted muscle that may bulge, feel rather firm, and feel very tender.
Treatment of the Cramp
If you can stretch the muscle, this is the best way to relieve the pain of the cramp. Cramps of the leg and foot can often be relieved by standing 
up and walking around. If you have a muscle in your calf, you can stand around from two to two and a half feet from a wall and lean towards the wall with your knees and back straight and your heels contacting the floor. Another way to relieve the cramp is by flexing your ankle by pulling your toes up toward your head while you are lying in bed with your leg as straight as you can make it. Also if you can massage the muscle, this may help it to relax. Using a heating pad on the affected area may also help. If you think it may be the result of dehydration, drinking fluids, particularly with electrolytes, is a good idea. Usually medicines are not necessary to treat a cramp because most cramps will get better before the medicine can be absorbed to have an effect.
Prevention of Muscle Cramps
The first way to prevent muscle cramps is through a
ctivity. It is recommended that you stretch before and after physical activity. You should always warm up before physical activity and cool down afterwards. You must also get enough to drink before, during, and after the activity. It is very important that you have replaced lost electrolytes, particularly potassium and sodium.
During pregnancy, supplemental doses of magnesium and calcium have prevented cramps. Be sure that before you begin taking a vitamin supplement that you first speak to your physician. Dystonic cramps can sometimes be avoided by avoiding high heels, changing your chair position, taking activity breaks, and avoiding excessive tension. Night cramps and rest cramps can usually be prevented by stretching, especially if you do so before going to bed. Also be sure that you are getting enough calcium and magnesium in your diet. For some women, an extra dose of calcium before bedtime may help them to prevent cramps.
