What Are Leg Cramps? What Cause Leg Cramps?

Leg cramps, also known as night leg cramps, especially calf-muscle cramps, are fairly common. Some people experience cramps in the muscles of their feet, as well as their thigh muscles. In most cases these types of cramps occur while the individual is sleeping or resting.

Leg cramps are sudden, painful involuntary contractions of a leg muscle. The cramp usually only lasts a few minutes, sometimes a few seconds. Rarely though, they can last up to 10 minutes. Sometimes the pain is so severe that the patient is woken up and has a tender muscle for up to 24 hours afterwards.

In most cases the reason for leg cramps is never found, and they are considered harmless. Sometimes, however, they may be linked to an underlying disorder, such as diabetes or peripheral artery disease.

As we get older we become more prone to experiencing leg cramps - about 1 in 3 people over the age of 60 years and half of people over 80 has regular leg cramps. Pregnant women tend to have night leg cramps more often than non-pregnant women. Approximately 40% of people who get leg cramps do so at least three times a week; in some cases they occur daily.

What are the causes of leg cramps?

Unknown causes (idiopathic leg cramps) - in the majority of cases there is no underlying cause and we don't really know why it happens. On theory is that when a muscle tightens for a prolonged period, resulting in the muscle being shortened, it is stimulated to contract, causing it to go into a spasm (cramp) if it contracts further. This occurs more commonly while we are sleeping - our natural sleep position is with the knees slightly bent and the feet pointing downwards (shortening the calf muscle). The fact that stretching helps cure the problem makes the theory more compelling.

Secondary causes - sometimes the leg cramps are caused by an underlying disease, situation or activity, including:

• Exercise - if a muscle is placed under severe stress or used for a long time a leg cramp may occur during the exertion or afterwards. Athletes and sportspeople commonly suffer from leg cramps, especially when having to work for longer than expected, as may happen in a soccer match that goes into extra time.
  
  If conditions are warm and the athlete has sweated profusely and lost a lot of sodium (salt), the risk of developing a muscle cramp is greater.
• Addison's disease
• Alcoholism or alcohol abuse
• Cirrhosis
• Dehydration
• Diarrhea
• Diuretics
• Electrolyte imbalance
• Flatfeet
• Gastric bypass surgery
• Hypothyroidism (underactive thyroid)
• Kidney failure, chronic
• Lead poisoning
• Sarcoidosis - a disease in which granulomatous (small growths or lumps) produces inflammation or swelling of the tissues in any part of the body.
• Muscle fatigue
• Motor neuron problems
• Oral contraceptives
• Parkinson's disease
• Peripheral artery disease (PAD)
• Pregnancy, especially in the later stages
• Some medications, including diuretics, salbutamol (used for treating asthma), and statins (used to lower blood lipid levels)
• Type 2 diabetes

Diagnosing leg cramps

A GP (general practitioner, primary care physician) will ask the patient about symptoms, when they occur, as well as examining his/her legs and feet. Questions will be related to how severe the pain is, where the pain is located, how long it lasts, and whether the leg cramps affect their quality of life (sleep, moods, etc).

The doctor will also ask about other possible symptoms, such as inflammation, numbness or pins and needles. The aim here is to either rule out or identify any possible underlying cause.

What are the treatment options for leg cramps?

If there is no underlying cause the leg cramps will probably get better without treatment.

Stretching exercises - if the cramp is in the calf muscle:

• Straighten the leg and bend the ankle backwards, thus stretching the calf muscle.
• Walk on tiptoes for a few minutes.
• Stand about one meter from a wall with your feet flat on the ground. Lean forward against the wall with your arms outstretched, but don't lift your heels (keep your heels on the ground). Stay like that for about ten seconds and gently return to an upright position. Repeat about 5 to 10 times.

Some people find that these stretching exercises not only help them get over a leg cramp episode, but also that help reduce how often they occur. Typically, a patient would do these exercises two or three times a day.

Painkillers - although painkillers can be effective in reducing pain, they take time to work. By the time they start working the leg cramp is probably gone. Therefore, they are probably not very useful. If an individual had a severe leg cramp and the muscle is tender afterwards, an OTC (over-the-counter, non prescription required) painkiller may help.

Quinine - some preliminary studies have found that a number of people benefit from taking quinine. There is no information yet about quinine's safety and long-term effectiveness. Some doctors may recommend quinine if the stretching has not helped, attacks are frequent, and/or the patient's quality of life is being undermined by the leg cramps. A course of treatment usually lasts from four to six weeks - the patient takes the medication just before going to bed.

Pregnant women should not take quinine. Individuals who had a previous reaction to quinine, those with previous hemolytic anemia, optic neuritis, and/or glucose 6-phosphate dehydrogenase deficiency should not take quinine.

As the quinine dosage is very low, side effects are rare. In rare cases the patient may develop a blood disorder. Some patients may develop cinchonism after long-term quinine therapy, which may cause vomiting, nausea, vision and/or hearing problems and dizziness.

Patients with leg cramps on quinine therapy are usually monitored closely.

Preventing leg cramps

Stretching exercises - these may help reduce the number of times leg cramps occur.

Supporting your toes when lying down or asleep:

• Lying on your back - prop up your feet with a pillow/cushion.
• Lying on your front - let your feet hang over the end of the bed.
• Bedding - keep blankets and sheets loose. This helps prevent your feet and toes from pointing downwards during sleep.

Stay hydrated - as dehydration may increase the risk of leg cramps, drinking plenty of fluids may help prevent them.

Exercise - if you embark on an exercise program, make sure it is suitable for you and that your progress is gradual. If you want to prevent leg cramps from occurring, do not over-exert yourself, or train for prolonged periods.

Footwear - people with flat feet and other structural problems may be more susceptible to leg cramps. Proper footwear may help.