Leg cramps are a common and usually harmless condition where the muscles in your leg suddenly become tight and painful.
It usually occurs in the calf muscles, although it can affect any part of your leg, including your feet and thighs.
After the cramping has passed, you may have pain and tenderness in your leg for several hours.
Three out of four cases occur at night during sleep.
Read more about the symptoms of leg cramps.
Leg cramps can occur for no apparent reason, known as idiopathic leg cramps, or as a symptom or complication of a health condition, known as secondary leg cramps.
Causes of secondary leg cramps can include:
During a cramp, your muscles suddenly contract (shorten), causing pain in your leg. This is known as a spasm, and you cannot control the affected muscle.
The cramp can last from a few seconds to 10 minutes. When the spasm passes, you will be able to control the affected muscle again.
Read more about the causes of leg cramps.
Speak to your doctor if your leg cramps are affecting your quality of life; for example, if you have frequent leg cramps or they are interfering with your sleep.
Your doctor will ask about your symptoms and examine your legs and feet. They may also ask if you have other symptoms, such as numbness or swelling, which may be a sign that you have secondary leg cramps caused by an underlying condition.
In this case, you may need further tests, such as blood tests and urine tests, to rule out other conditions.
Most cases of leg cramps can be relieved by exercising the affected muscles. Exercising your legs during the day will often help reduce how often you get cramping episodes.
To stretch your calf muscles, stand with the front half of your feet on a step, with your heels hanging off the edge. Slowly lower your heels so that they are below the level of the step. Hold for a few seconds before lifting your heels back up to the starting position. Repeat a number of times.
Medication is usually only needed in the most persistent cases where cramping does not respond to exercise.
If you have secondary leg cramps, treating the underlying cause may help relieve your symptoms.
Leg cramps that occur during pregnancy should pass after the baby is born.
Treating cramps that occur as a result of serious liver disease can be more difficult. Your treatment plan may include using medications such as muscle relaxants.
Read more about treating leg cramps.
If you often get leg cramps, regularly stretching the muscles in your lower legs may help prevent the cramps or reduce their frequency.
You might find it useful to stretch your calves before you go to bed each night (see stretching advice above).
The following night-time advice may also help:
A leg cramp is an episode of sudden and severe pain in the muscles of the leg caused by an involuntary contracting (shortening) of the leg muscle.
Most leg cramps occur in the calf muscles and, less commonly, in the feet and thighs.
Cramps can last from a few seconds up to 10 minutes. Thigh muscle cramps tend to last the longest.
During a cramping episode, the affected muscles will become tight and painful and the feet and toes will be stiff.
After the cramps have passed, you may have pain and tenderness in your legs for several hours.
If you only get leg cramps occasionally, it is not a cause for concern and a medical diagnosis is not required.
A visit to your doctor will only be necessary if you get leg cramps frequently, or if they are so painful they disrupt your sleep and you are unable to function normally the next day.
You should also visit your doctor if the muscles in your legs are shrinking or becoming weaker.
There are two situations where leg cramps may be a sign of a more serious underlying health condition.
You should seek immediate medical help if:
In these circumstances, contact your doctor for advice immediately. If this is not possible, contact your local out-of-hours service.
The cause of leg cramps is sometimes unknown (idiopathic). In other cases, there may be an underlying condition or another identifiable cause.
Although the cause of idiopathic leg cramps is unknown, there are a number of theories about what might cause idiopathic leg cramps. These include:
Also, tendons naturally shorten over time as a person gets older, which may explain why older people are particularly affected by leg cramps. Tendons are tough bands of tissue that connect muscles to bone. If your tendons become too short, they may cause the muscles connected to them to cramp.
Secondary leg cramps are caused by an underlying condition or another identifiable cause. These include:
Certain medications have been known to cause leg cramps in a small number of people. These include:
Contact your doctor if you think your medication may be causing your leg cramps as your dosage may need to be adjusted. Never stop taking a prescribed medication unless your doctor or another qualified healthcare professional who is responsible for your care advises you to do so.
If the cause of your leg cramps is known, it may be possible treating the underlying cause.
For example, secondary leg cramps that are related to liver disease are caused by high levels of toxins in the blood which trigger muscles spasms. Therefore, muscle relaxants can be used to help prevent your muscles from going into spasm.
If the cause of your legs cramps is unknown (primary idiopathic leg cramps), a combination of exercise and painkilling medication is usually recommended.
Most cases of leg cramps can be treated with exercises. There are two types of exercise that you can do:
The two types of exercises are explained below.
During an episode of leg cramp, stretch and massage the affected muscle.
For example, if the cramp is in your calf muscle:
To reduce your risk of getting leg cramps in the future, you should do exercises to stretch the affected muscles three times a day.
For example, if your calf muscles are affected by cramps, the following exercise should be beneficial:
For the best results, you should repeat this exercise three times a day, including one session just before you go to bed.
If you find these exercises useful you can carry on doing them for as long as you are able to.
Quinine is a medication that was originally designed to treat malaria. Subsequent research has found that it can also be moderately effective in reducing the frequency of leg cramps.
However, there is a small chance that quinine may cause unpleasant side effects including:
Thrombocytopenia is a rarer but more serious complication of quinine. It occurs when the number of platelets in your blood falls to a dangerously low level. Platelets help the blood to clot which means that people with thrombocytopenia are at increased risk of excessive bleeding such as:
There have been a number of reported cases of people dying from thrombocytopenia after taking quinine to prevent leg cramps.
Never take more than your recommended dose of quinine. An overdose of quinine can result in permanent blindness and death.
Due to these small but potential risks, your doctor will only prescribe quinine if there is evidence that the potential benefit of treatment outweighs the risks.
It is recommended that quinine is only prescribed when:
In these circumstances, you may be prescribed a four-week course of quinine. After this time, if you have not gained any benefit, the treatment will be withdrawn.
If you experience any of the side effects listed above, stop taking quinine immediately and contact your doctor.
Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.