Foot Cramps

What is it?

A cramp is a muscle that suddenly tightens and won't relax. It hurts, and you may feel a hard knot in the muscle. A foot cramp can affect the sole of your foot or your toes, and often the calf (the muscle at the back of your lower leg) is involved too.

Most cramps last from a few seconds to a few minutes. Some last up to 10 minutes, and a few up to 15. A cramp may come back a few times before it goes away completely.

Most cramps happen when you are resting, mainly at night. Cramps in the leg are common and usually harmless, but they can be very painful and can disturb your sleep.

What can cause it?

Often no clear cause is found. Cramps can come out of nowhere, even in people who are otherwise well.

These are some of the things linked to cramps, starting with the most common:

• Tired or overworked muscles. Straining your muscles during exercise can bring on cramps, and this can be worse in hot or humid weather.
• Some medicines. Water tablets (diuretics), cholesterol medicines (statins) and some asthma inhalers (beta-agonists) are linked to cramps.
• Later pregnancy. Cramps are more common in pregnancy, usually in the later months.
• Not drinking enough, or an imbalance of body salts. These salts, called electrolytes, include sodium, calcium, magnesium and potassium. How much they matter isn't clear, and the exact cause of cramps isn't known. An underactive thyroid (hypothyroidism) is another cause that can be put right.
• Ageing, tight muscles and poor fitness. Short, tight muscles in older people who are less active may make cramps more likely.
• Some health conditions. Liver failure, kidney failure treated with dialysis (especially when a lot of fluid is removed) and problems with blood flow in the legs are linked to cramps.

Some other problems can feel like cramps or exist alongside them. These include restless legs syndrome, poor blood flow to the leg or foot, muscle inflammation, nerve damage in the feet and legs (peripheral neuropathy), and a slipped disc in the lower back.

Who gets it?

Foot and leg cramps can happen to anyone. They are more common in older people, in pregnant women and in people who exercise hard.

Among adults aged 60 and older who see their GP, cramps are common. Only some have them more than once a week, but many say cramps disturb their sleep.

You may be more likely to get them if you take certain medicines, or if you have liver, kidney or circulation problems.

How is the cause found?

Your podiatrist or GP will mostly work it out by talking with you and examining you. They will ask where and when the cramps happen, whether they come with activity, and whether they are mostly in the day or at night. They will ask about your health and your medicines. They may also ask about weakness, numbness or swelling.

They will then look at your legs and feet. This usually includes checking your circulation and your nerves.

Brief, intense pain in the calf or foot that eases without you doing anything is typical of a cramp. It helps tell cramps apart from restless legs. Pain in the calf or foot while resting or sleeping can sometimes come from poor blood flow instead, so it is worth mentioning.

Blood and urine tests may be needed if an underlying cause is suspected. They are often not needed to confirm ordinary night-time leg cramps.

It helps to bring a list of all your medicines, including inhalers and water tablets. Note when your cramps happen, how long they last, which part of your leg or foot is affected, and what you were doing. Tell your practitioner if you have liver, kidney or circulation problems, are pregnant, or have recently started a new medicine.

Treatment

Cramps usually pass by themselves. Non-drug measures are the first step, and medicines come later, if at all.

Looking after it at home

When a cramp starts, gently stretch or massage the muscle. It will usually pass on its own.

If your cramps come at night, daily stretching of your calf and hamstrings (the muscles at the back of your thigh) for six weeks may make night-time cramps less severe in people aged 55 and older. Its effect on how often cramps happen is not clear. Calf stretching alone for 12 weeks may make little difference to how often cramps happen in people aged 60 and older. If you try stretching, treat any benefit as uncertain.

If a medicine might be causing your cramps, don't stop it on your own. Check with your doctor or pharmacist first.

Other options

If simple measures aren't enough, talk with your doctor or pharmacist before taking any medicine or supplement for cramps. Ask them to review your current medicines first, and to check for causes that can be put right, such as an underactive thyroid or an imbalance of body salts.

Magnesium. Magnesium supplements are unlikely to prevent cramps in older adults. They don't appear to help night-time leg cramps in most people, though they may have a small effect in pregnancy.

Quinine. Quinine is a prescription medicine. It isn't for routine use, and some advice says it is no longer recommended for leg cramps. Where it is considered, it is only for people whose cramps regularly disturb their sleep. It can affect the rhythm of your heart and can interact with other medicines. Only a doctor should prescribe it, and never use someone else's tablets or leftover supplies.

Will it get better?

Yes, in most cases. A cramp generally goes away by itself, though how long it lasts varies. It isn't clear yet how often foot cramps come back.

Cramps that keep happening, that are severe, or that last longer than a few minutes should be looked at by a doctor. Sometimes they are a sign of an underlying problem, such as narrowed arteries.

It helps to keep a note of how often your cramps happen. That way you can tell if they are becoming more frequent or lasting longer, and show your doctor if they are. If cramps are disturbing your sleep, raise this with your GP.

Preventing it

No method has been shown to stop cramps coming back. Daily calf and hamstring stretching may ease how bad night-time cramps are. Magnesium is unlikely to help prevent them in older adults.

If your cramps come with exercise, look at how hard you are pushing your muscles, especially in hot or humid weather. Review your medicines with your doctor or pharmacist, as some are linked to cramps.

When to see a podiatrist

Book an appointment if

Book an appointment with your podiatrist if foot cramps keep coming back, or if they get in the way of your sleep, walking or exercise and you'd like help working out why. See your GP soon if your cramps are frequent or very painful, if they disturb your sleep, if they come with numbness or swelling in your legs, if you get regular or severe cramping that lasts longer than a few minutes, or if you have weakness along with cramps or twitching. Sometimes cramps are a sign of another health problem, such as narrowed arteries, and a doctor can check.

Seek prompt assessment if

Call your local emergency number if you have chest pain, trouble breathing, or signs of a stroke or heart attack. Call it too if your leg, foot or toes suddenly turn cold and pale or blue, with pain or numbness, or if you suddenly can't move your leg or foot. If you have an infection or a foot wound and you also feel confused, have slurred speech or can't make sense when you speak, this could be sepsis: call your local emergency number. If you have new trouble controlling your bladder or bowels, numbness around your genitals or back passage, or trouble walking, go to the nearest emergency department, even if you have no pain. See your GP or another doctor today if your calf is painful, swollen, warm or red, especially on one side, or after sitting for a long time, such as on a flight. Don't wait to see if it settles. See a doctor today too if a cramp lasts longer than 10 minutes and doesn't ease with stretching or movement, if it starts after contact with something that may be toxic or infectious, if you have a foot sore that won't heal, or constant foot pain at rest, or if you have cramps or sore muscles with dark urine after a heavy endurance event. If your GP can't see you today, go to an urgent care clinic or an after-hours GP.

Frequently asked questions

Why do foot cramps often happen at night?

Most cramps happen when you are resting, and about three in four leg cramps happen during sleep. Night-time cramps are common in older people and in later pregnancy. If they keep waking you, mention it to your GP, as there may be something that can be put right, such as a medicine.

Does having foot cramps mean something serious is wrong?

Usually not. Cramps are common and usually harmless, and often no cause is found. Sometimes they come from a health problem, such as poor circulation, so it is worth having frequent, severe or long cramps checked. Check the warning signs under "When to see a podiatrist" and follow the advice given for each one, including calling your local emergency number or seeing a doctor today where it says so.

Should I drink more water or take electrolyte drinks to stop cramps?

Not drinking enough may play a part in some cramps, but the cause isn't certain. Don't over-drink or overuse electrolyte products to try to prevent cramps, as too much can cause harm. If you exercise hard and get cramps often, talk with your doctor or another health professional about safe drinking.

Further reading

• Foot pain: MedlinePlus Medical Encyclopedia MedlinePlus
• Leg cramps NHS
• Muscle cramp Better Health Channel