What is Leg cramps?

Leg cramps

What are leg cramps?

People who get a leg cramp feel a sudden pain in their leg, often at night.

This happens when a muscle or group of muscles suddenly tightens (contracts).

Source:
Young G.
Leg cramps.
Clinical Evidence. 2006; 15: 1613-1618.

¹ 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.

Most cramps happen in calf muscles.

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.

Source:
Mandal AK, Abernathy T, Melluri SN, et al.
Is quinine effective and safe in leg cramps?
Journal of Clinical Pharmacology. 1995; 35: 588-593.

² You won't know how long they'll last.

Source:
Mandal AK, Abernathy T, Melluri SN, et al.
Is quinine effective and safe in leg cramps?
Journal of Clinical Pharmacology. 1995; 35: 588-593.

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 sick. But the following things can make you more likely to get painful cramps:

Source:
Young G.
Leg cramps.
Clinical Evidence. 2006; 15: 1613-1618.

Source:
Mandal AK, Abernathy T, Melluri SN, et al.
Is quinine effective and safe in leg cramps?
Journal of Clinical Pharmacology. 1995; 35: 588-593.

Being pregnant
Being middle-aged or older
Exercising
Not having certain salts in your body
Having dialysis (this is when a machine is used to clean your blood because your

kidney
Your kidneys are organs that filter your blood to make urine. You have two of them, on either side of your abdominal cavity, toward your back.

kidneys aren't working properly)
Having an imbalance of 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 blood pools in the veins)
Having damaged nerves or a disease that affects your nerves
Having a disease that affects your muscles.

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

Source:
Butler JV, Mulkerrin EC, O'Keefe ST.
Nocturnal leg cramps in older people.
Postgraduate Medical Journal. 2002; 78: 596-598.

Diuretics
Nifedipine
Beta-agonists
Steroids
Morphine
Cimetidine
Penicillamine
Statins
Lithium.

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).

A blood clot in your leg also can cause leg pain. This is known as deep vein thrombosis (DVT) and it is more serious than a leg cramp. You will need medication to treat the clot and keep it from causing serious problems. If you get swelling as well as pain in your calf or thigh, you might need an

ultrasound
Ultrasound is a tool doctors use to create images of the inside of your body. The ultrasound machine sends out high-frequency sound waves, which are directed at an area of your body through a device such as a probe. The waves reflect off parts of your body to create a picture. Ultrasound is often used to see a developing baby inside a woman's womb.

ultrasound scan to see if there's a blood clot in your leg. To learn more, see our articles on Deep vein thrombosis.

Sources for the information on this page:

Young G.Leg cramps.Clinical Evidence. 2006; 15: 1613-1618.

Mandal AK, Abernathy T, Melluri SN, et al.Is quinine effective and safe in leg cramps?Journal of Clinical Pharmacology. 1995; 35: 588-593.

Butler JV, Mulkerrin EC, O'Keefe ST.Nocturnal leg cramps in older people.Postgraduate Medical Journal. 2002; 78: 596-598.

This information was last updated on Apr 09, 2009

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