Leg cramps are common. The cause is not known in most cases. However, some drugs and diseases sometimes cause leg cramps. Regular calf stretching exercises may prevent leg cramps. Quinine tablets may be advised as a last resort if you have cramps regularly.

What are leg cramps?

A leg cramp is a pain that comes from a leg muscle. It is due to a muscle spasm which is when a muscle contracts too hard. It usually occurs in a calf muscle, below and behind a knee. The small muscles of the feet are sometimes affected.

A cramp pain typically lasts a few minutes. In some cases it lasts just seconds, but in some cases it lasts up to 10 minutes. The severity of the pain varies. The muscle may remain tender for up to 24 hours after a leg cramp. Leg cramps usually occur when you are resting - most commonly at night when in bed. (They are often called night cramps.) They may wake you. It can become a distressing condition if your sleep is regularly disturbed.

Who gets leg cramps?

Many people have an occasional leg cramp. However, they occur frequently in some people.

They are more common in older people. About 1 in 3 people over the age of 60, and about half of people over the age of 80, have regular leg cramps. About 4 in 10 people who have leg cramps have at least three per week. They occur every day in some people.

What causes leg cramps?

Unknown cause (idiopathic leg cramps)

In most cases the cause is not known. One theory is that cramps occur when a muscle that is already in a shortened position is stimulated to contract. As the muscle is already shortened, to contract further may cause the muscle to go into spasm. This commonly happens at night in bed as the natural position we lie in is with the knees slightly bent (flexed), and with feet pointing slightly downwards. In this position the calf muscle is relatively shortened and may be prone to cramps. This theory explains why stretching exercises may cure the problem.

Secondary causes

In some cases, the cramps may be a symptom of another condition or problem. For example:

• Over-exertion of muscles.

• Dehydration.

• Sports, excess long term house-hold activities

  • Some drugs can cause cramps as a side-effect, or make cramps occur more often. These include: diuretics ('water tablets'), nifedipine, cimetidine, salbutamol, statins, terbutaline, lithium, clofibrate, penicillamine, phenothiazines, and nicotinic acid.

  • Conditions that cause alterations in the balance of salts in the bloodstream (such as a high or low sodium or potassium level).

  • Some people who have renal (kidney) dialysis get leg cramps.

  • Pregnancy - usually in the later stages.[

  • An untreated under-active thyroid gland.

  • Peripheral vascular disease (narrowing of the leg arteries which causes poor circulation).

  • Excess alcohol.

  • Some uncommon disorders of nerves.

  • Rare causes include: cirrhosis of the liver; lead poisoning; sarcoidosis.

With the above conditions the cramps would just be one of various other symptoms. Therefore, if you are otherwise well, and have no other unexplained symptoms, then the leg cramps are likely to be idiopathic (unknown cause) and not due to a secondary cause.

Note: leg cramps are different to a condition called restless legs syndrome. In this condition the legs can be uncomfortable, you feel creeping sensations in the legs, and it is relieved by walking about. See separate leaflet called 'Restless Legs Syndrome' for details.

http://www.bbc.com/news/health-33223045

http://www.bbc.co.uk/newsbeat/article/33237269/skinny-jeans-and-other-hidden-health-risks-in-your-wardrobe

Skinny jeans can seriously damage muscles and nerves, doctors have said.

A 35-year-old woman had to be cut out of a pair after her calves ballooned in size, the medics said in the Journal of Neurology, Neurosurgery and Psychiatry.

She had spent hours squatting to empty cupboards for a house move in Australia. By evening, her feet were numb and she found it hard to walk.

Doctors believe the woman developed a condition called compartment syndrome, made worse by her skinny jeans.

What is the treatment for a leg cramp?

Stretching and massaging the affected muscle can usually relieve an attack of cramp. Most cramps soon ease off.

Painkillers are helpful.

Painkiller such as paracetamol may help to ease muscle discomfort and tenderness that sometimes persists for up to 24 hours after a cramp has gone.

What are the options for preventing leg cramps?

If cramps do not occur often, then no particular treatment is usually needed. However, if you have frequent cramps, you may wish to consider ways of preventing them.

Consider your medication (where appropriate) or other conditions

Tell your doctor if you take any of the drugs listed earlier. It may be causing the leg cramps, or making them recur more often. Alternative drugs may be available. Also, if you have other symptoms apart from cramps, see your doctor who may examine you or do some checks to rule out a secondary cause for the cramps.

Stretching exercises

Quinine is used as a last resort - and you need to be aware of the risks

If you take quinine you have a good chance of reducing the number and/or severity of leg cramps, but it may not stop them altogether. One tablet at bedtime is the normal dose. Most people can take quinine, but do not take it if you are pregnant or may become pregnant. There are also some rare conditions where you should not take quinine. These include: a previous reaction to quinine; a previous haemolytic anaemia; optic neuritis; glucose 6-phosphate dehydrogenase deficiency.

Side-effects are uncommon at the low dose used to treat leg cramps. However, serious side-effects do sometimes occur. For example, a serious blood disorder which is potentially fatal is a known rare side-effect. Also, a small number of people who take quinine long-term develop a condition called cinchonism (a complex of nausea, vomiting, dizziness, visual disturbance, and hearing impairment). Read the drug packet leaflet for a full list of possible side-effects. Note: quinine is dangerous in overdose, particularly in children. Keep tablets away from children.

Therefore, quinine is only used as a 'last resort' when other treatments have not worked, and leg cramps are frequent and are affecting your quality of life.

When quinine is first prescribed it may be done on a trail basis for 4–6 weeks. You should be aware of the small risk of serious side effects. Also, it is best to objectively assess how well the quinine works. For example, by keeping a sleep and cramp diary. Ideally, this should be for a few weeks before and after the start of treatment so as to gauge its effect. If quinine is found to help then you may be advised to continue with it for a few months. You should consider stopping quinine every three months or so to see if it is still needed. This is because in some people the cramps go away and so the treatment may no longer be needed. If the cramps return, you can always re-start the tablets.

Other treatments

Other drugs have been suggested as possible treatments for leg cramps. These include: magnesium, diltiazem, vitamin B complex, vitamin E, naftidrofuryl, orphenadrine, and verapamil. In general, these are not currently recommended as most studies involving them found that they do not work very well in most people. Quinine remains the main treatment. However, your doctor may suggest a trial of one of these drugs if quinine has not worked or has caused troublesome side-effects.

References

• • Leg cramps, Clinical Knowledge Summaries (November 2008)

  • J V Butler, E C Mulkerrin, S T O’Keeffe; Nocturnal leg cramps in older people Postgrad Med J 2002;78:596–598

  • Daniell HW; Simple cure for nocturnal leg cramps. N Engl J Med. 1979 Jul 26;301(4):216.

  • Coppin RJ, Wicke DM, Little PS; Managing nocturnal leg cramps--calf-stretching exercises and cessation of quinine treatment: a factorial randomised controlled trial. Br J Gen Pract. 2005 Mar;55(512):186-91. [abstract]