Muscle cramps are very common, particularly in the legs. Leg cramps commonly affect your calf muscles (at the back of your leg, below the knee). However, they can also affect thigh muscles and sometimes the small muscles in your feet. Leg cramps usually happen while you are resting or sleeping.

What are leg cramps?

A leg cramp occurs when your muscles suddenly shorten (contract), giving you pain in your leg. This is called a spasm, and you're unable to control the affected muscle when it happens.

The cramp can last from a few seconds to 10 minutes. When the spasm passes, you'll be able to control the affected muscle again.

The cause of leg cramps is often unknown, and treatment isn't usually needed. Self-care techniques, such as stretching exercises, can help reduce them.

Who gets leg cramps?

Many people get leg cramps. They can affect people of any age, although they're more common in older people. One-third of people aged over 60 get leg cramps, with 40% of those having it three or more times a week.

If you have leg cramps, you will feel pain in your leg muscles. The cramp may affect the muscles in your:

• Calf.
• Thigh.
• Feet.

During a leg cramp, you will feel a painful muscle spasm that you can't control. The spasm may go after a few seconds or a few minutes. The muscle will often feel hard and painful, and it may remain tender for up to 24 hours after the cramp.

Leg cramps occur as a result of a prolonged tightening of a muscle, leading to the muscle being shortened.

Most leg cramps have no underlying cause. However, exercise and (in rare cases) underlying health conditions may cause leg cramps. Certain medications may also cause leg cramps.

Exercise

Leg cramps sometimes occur during or after vigorous exercise, where the muscles are placed under severe stress or are used for prolonged periods of time.

Leg cramps are a common problem for athletes, such as sprinters, distance runners and footballers.

Excessive sweating during exercise, particularly in warm conditions, can lead to a loss of sodium (salt), which often causes cramp.

Underlying conditions

Occasionally, leg cramps may occur as a result of an underlying condition, such as:

• Motor neurone problems (problems with nerve cells in the lower part of your body that control muscle action).
• Metabolic problems, such as liver, kidney or thyroid conditions.
• Dehydration.

If your leg cramps are caused by another condition, you will probably have other symptoms along with the leg cramps.

If your GP thinks that another condition may be causing your leg cramps, you may need to have some tests. Your GP may refer you to a specialist.

Medication

Some types of medication can cause leg cramps. For example:

• Diuretics.
• Salbutamol: medicine that is used to treat conditions such as asthma.
• Statins: medicines that lower the level of fats (lipids) in your blood.

You should visit your GP if you're taking medication and you start to get frequent leg cramps.

You should visit your GP if your leg cramps are affecting your quality of life. For example, see your GP if you have frequent leg cramps, or they are affecting your sleep.

Making a diagnosis

When you visit your GP with leg cramps, they will ask you about your symptoms and examine your legs and feet. Your GP may ask you:

• About the pain in your calf, thigh or foot, and how severe it is.
• Whether the pain comes on suddenly.
• How long the pain lasts.
• Whether your leg cramps are affecting your sleep, mood and quality of life.

Your GP may also ask if you have any other symptoms, such as numbness or swelling. This is because in rare cases, leg cramps can be caused by some health conditions and certain types of medication. See the ‘complications’ section for more information about this.

Leg cramps with no underlying cause often get better without any treatment.

Your GP may give you advice to help you ease your leg cramps when they happen, and reduce how often they happen.

See the ‘self help’ section for more information.

Can painkillers help?

Most leg cramps come on suddenly and do not last very long. Therefore, painkillers are unlikely to help because the cramp will probably have passed before the drugs take effect.

However, if a severe leg cramp leaves your muscle feeling tender afterwards, you could take a painkiller such as paracetamol.

Quinine

Research has shown that for some people, quinine may be effective in treating leg cramps. However, more research is needed in order to assess its long-term effectiveness and safety.

Treatment with quinine is known to run the risk of possible side effects, including:

• Tinnitus (the perception of noise in the ear or head).
• Upset stomach.

However, these side effects are more usually associated with higher doses of quinine, such as those that are used to treat malaria, rather than the dosage that is used to treat leg cramps.

Your GP may consider a trial of treatment with quinine if:

• Your leg cramps have not improved after following the self-help advice.
• You have frequent attacks of leg cramps.
• Your leg cramps are affecting your quality of life.

Your GP will not recommend quinine unless they think that the possible benefits will outweigh the risks of side effects.

If you're prescribed quinine, you will probably need to take it at bedtime for four to six weeks. Your GP will advise you about what dose to take and when to take it.

Your treatment will be monitored closely and reviewed regularly. For example:

• You may be asked to keep a ‘sleep and cramp’ diary to check how often you are getting leg cramps.
• Your GP is likely to review your initial treatment after three months.
• If your condition improves, your GP may re-assess your treatment needs every three to six months.

The advice below may help you to ease your leg cramps and reduce how often you get them.

Stretching exercises

If you get a leg cramp, try stretching and massaging the affected muscle. For example, if the cramp is in your calf muscle:

• Straighten your leg and bend your ankle backwards.
• Try walking around on tiptoes for a few minutes.

Below is another exercise to help stretch your calf muscles.

• Lean forward against a wall with your arms outstretched, about a metre (39 inches) from the wall.
• Keep the soles of your feet flat on the floor for five seconds.
• Repeat this exercise several times, for about five minutes.

Stretching exercises can also help to reduce how often you get leg cramps. Try doing the exercises three times a day, including just before you go to bed.

If these exercises improve your cramps and reduce how often they occur, you may be able to do the exercises just once or twice a day.

If you get leg cramps frequently, stretching exercises may help to prevent them or reduce how often you get them.

Supporting your toes

Supporting your toes while you're asleep may also help you to prevent getting cramp in your legs. The following advice may be helpful to you:

• If you're lying on your back, prop your feet up with a pillow.
• If you're lying on your front, hang your feet over the end of the bed. This will keep your feet in a relaxed position and help to stop the muscles in your calves from contracting and tensing.
• Keep your blankets and bedding loose.