Muscle cramps

Last published:Jan 07, 2021

Leg cramps are not usually serious and you might not need treatment. But if your leg cramps are troublesome and stop you sleeping, there are treatments that you can try.

What are leg cramps?

People who get a leg cramp feel a sudden pain in one or both legs, often at night.

This happens when a muscle or group of muscles suddenly tightens (contracts). This is called a muscle spasm. Most cramps happen in calf muscles, but you can also get cramps in your thigh or in your foot.

Leg cramps usually happen at night or when you are resting. The muscle contractions can last for a few seconds or up to 10 minutes.

What else can cause leg pain?

Cramps aren't the only cause of leg pain. You can also get severe calf pain after an injury, or if you have a Baker's cyst that bursts (a Baker's cyst is a lump of fluid that forms behind the knee).

If you have leg pain that is severe, lasts more than 10 minutes, and is accompanied by redness, swelling, and fever, you should seek medical help immediately. It could be a sign of something more serious.

Why do I get leg cramps?

We don't know very much about what causes leg cramps or why certain people get them. Most people who have these pains in their legs are not ill. But some things can make you more likely to get painful cramps, including:

• being pregnant

• being aged 60 or older

• doing vigorous exercise

• having dialysis (this is when a machine is used to clean your blood because your kidneys aren't working properly)

• having an imbalance of some salts and minerals in your body (this is called an electrolyte imbalance)

• having problems with your blood circulation or having varicose veins in your legs (varicose veins happen when valves in veins don't work properly, so that blood pools in the veins)

• having damaged nerves or a disease that affects your nerves, such as motor neuron disease

• having a disease that affects your muscles, such as multiple sclerosis

• having diabetes (leg cramps can happen if your blood sugar gets too low, which is called a hypoglycaemic episode, or 'hypo').

Some medicines can cause leg cramps as a side effect. They include:

• diuretics

• nifedipine

• beta-agonists

• corticosteroids (often just called steroids)

• morphine

• cimetidine

• penicillamine

• statins

• lithium.

What are the symptoms of leg cramps?

Leg cramps often happen at night. You'll probably feel a sharp pain that might wake you from your sleep. This happens most often in the calf muscle.

Here are some of the signs of a leg cramp:

• The main symptom is pain that comes on suddenly

• You will probably feel your calf muscle hardening

• The pain from the muscle tightening (contracting) can last for just a few seconds or up to 10 minutes

• Your muscle might be sore for up to 24 hours afterwards

• Only one leg is usually affected.

What will happen to me?

Leg cramps can be annoying or can disturb your sleep. But they aren't likely to cause any serious problems. They usually go away quite suddenly on their own.

You can be in a lot of pain and keep waking up at night because of sudden muscle spasms in a part of your leg, probably your calf. And you might get cramps for several weeks. But most people find their leg cramps suddenly go away.

If you get leg cramps while you're pregnant you'll probably find that they are more troublesome later in pregnancy, especially at night. But you'll probably stop having leg cramps as soon as you've had your baby.

Last published:Jan 07, 2021

Leg cramps are painful muscle contractions (spasms). They're not usually serious and you might not need treatment. But if your leg cramps are troublesome or if they stop you sleeping, there are treatments that you can try.

We've brought together the best research about leg cramps and weighed up the evidence about how to treat and prevent them. You can use our information to talk to your doctor and decide which treatments are best for you.

Short-term treatment

The simplest way to relieve cramps in the short term is to gently stretch the muscles that are affected. Rubbing the muscles can also help. If you’re able to, you could try putting all your weight on the painful leg for a few minutes.

Painkillers, yes or no?

Although taking painkillers such as paracetamol or ibuprofen might seem like a good way to treat painful leg cramps, these medicines might not do you any good. This is because the spasm that causes the pain is likely to be over by the time the painkiller starts working.

Preventing leg cramps

You may be able to take steps to prevent cramps that keep coming back. However, what steps you take will depend on what is causing your cramps. It might mainly involve treating the condition that is causing the cramps.

Leg cramps from an unknown cause

There isn’t much good research on how to prevent the return of cramps with an unknown cause.

Many treatments have been used to try to prevent this type of cramp. Research suggests that the most effective might be:

• a drug called naftidrofuryl that’s sometimes used to treat a condition called peripheral arterial disease

• vitamin B complex supplements

• a drug called diltiazem that is often used to treat high blood pressure and a type of heart pain called angina.

You can discuss with your doctor whether any of these treatments might be the right one for you.

Leg cramps caused by exercise

Drinking plenty of fluids before exercising may help prevent leg cramps.

If you still get leg cramps after exercising:

• rest in a room that’s at a comfortable temperature and not stuffy

• gently stretch the affected muscles

• if your urine is dark, drink a sports drink and eat a salty snack.

If, after exercising, you have very severe cramps, feel very faint and dizzy, and feel either very hot or very cold, you should get medical attention right away.

Leg cramps linked to diabetes

If you have diabetes, you may get leg cramps during a hypoglycaemic episode (or 'hypo'), where your blood sugar gets too low. The simplest way to treat the cramps is to treat the hypo, by having a sugary drink or snack.

Good blood sugar control may help prevent more hypos and leg cramps. This could mean adjusting your diet, avoiding alcohol, and talking with your doctor to make sure you are taking the right medicines for you.

Leg cramps during pregnancy

Changes in the body during pregnancy can cause leg cramps. These usually stop after the birth.

Some doctors recommend magnesium salts supplements for preventing leg cramps in pregnancy. But high doses can cause diarrhoea. Vitamin B supplements may also help. However, you shouldn’t take any medicines, vitamins, or supplements while you're pregnant unless they are recommended by your doctor.

Leg cramps linked to dialysis

Some people get leg cramps when they have a treatment called dialysis. This treatment uses a machine to clean your blood if your kidneys don’t work properly.

There are treatments that can help prevent cramps caused by dialysis. For example, a combination of vitamin E and vitamin C supplements may help some people.

Another treatment that may help is a medicine called quinine. But this drug can have serious side effects, including nausea, headaches, dizziness, diarrhoea, liver damage, and sometimes blindness. Because of this, in some countries, including the US, it is not used for leg cramps, or is used only as a last resort.

Leg cramps caused by cirrhosis

Cirrhosis is a type of liver damage that’s usually caused by drinking too much alcohol over many years. It can cause leg cramps in some people. Zinc sulphate or vitamin E supplements are sometimes recommended for prevention.

Leg cramps caused by conditions that affect the muscles or nerves

Conditions such as multiple sclerosis (MS) and motor neuron disease can cause leg cramps.

There are many medicines and supplements you can try for preventing cramps if you have one of these conditions, but research has not given a clear picture about what works best. Possible treatments include muscle relaxers, drugs that are usually used for epilepsy, or antidepressants. You can talk with your doctor about what might work best for you.