Leg cramps also know as night cramps or Charley Horse – are painful spasms that typically occur in the calf muscles. Leg cramps tend to jolt a person awake in the middle of the night, but can also strike in the daytime during physical activities such as running and cycling.
Fitness can put strain on your leg muscles. Some leg muscle cramps – which can last anywhere from a few seconds to up to 10 minutes – may also be the result of a sedentary lifestyle.
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.
The symptoms of a muscle cramp include:
- Sudden sensation of uncontrollable and painful spasms in the muscle
- Muscle twitching
- Minerals and electrolytes
Muscle tissue relies, in part, on a range of minerals, electrolytes and other chemicals in order to contract and relax. Some of these important substances include calcium, magnesium, potassium and sodium. Inadequate diet, dehydration, vomiting and diarrhoea are just some of the factors that are thought to disturb the body’s balance of minerals and electrolytes, and make muscles more susceptible to cramping.
Tetany is a special form of cramping – it can be brought on by overbreathing, which results in a low level of carbon dioxide in the blood. It is usually caused by anxiety.
The exact cause of muscle cramp is not known, but risk factors may include:
- Tight, inflexible muscles
- Poor physical condition
- Poor muscle tone
- Inadequate diet
- Physical overexertion
- Physical exertion of cold muscles
- Muscle injury
- Muscle fatigue
- Excessive perspiration
- Dehydration – caused by, for example, a bout of gastroenteritis
- Reduced blood supply (ischaemia)
- Wearing high-heeled shoes for lengthy periods.
- Muscle cramp associated with medical conditions
Certain diseases or conditions may increase the risk of muscle cramp, including:
- Atherosclerosis – a condition characterised by narrowed arteries due to the formation of fatty plaques. Muscles are more likely to cramp if their blood supply is inadequate.
- Sciatica – pain in the buttock and leg caused by pressure on nerves in the lower back. In some cases, the irritated nerve may prompt the associated muscles to contract.
- Medications – some medical conditions require the regular use of fluid pills (diuretics). These drugs can interfere with the body’s mineral balance and contribute to cramping.
- Treatment options
Most muscle cramps resolve after a few seconds or minutes. There has been very little research done to work out which treatment works best but treatment options include:
- Stretch and massage – lengthen the cramping muscle using a gentle, sustained stretch then lightly massage the area until the cramp subsides. If you are unsure how to stretch leg muscles, see your physiotherapist for advice.
- Icepack – in cases of severe cramp, an icepack applied for a few minutes may help the muscle to relax.
- Medication – some medications can be helpful to control muscle cramps. See your doctor for further information.
- Further treatment – see your doctor if you experience regular muscle cramping or if cramps last longer than a few minutes. You may have an undiagnosed medical condition that requires treatment.
- Prevention strategies
Suggestions on how to reduce the likelihood of muscle cramp include:
- Increase your level of physical fitness.
- Incorporate regular stretching into your fitness routine.
- Warm up and cool down thoroughly whenever you exercise or play sport.
- Drink plenty of water before, during and after exercise.
- Make sure your diet is nutritionally adequate, and include plenty of fruits and vegetables.
- A regular massage may help to reduce muscle tension.
- Wear properly fitted shoes and avoid high heels.
What Causes Muscle Cramps in the Calves
“Leg cramps can be caused by many conditions, ranging simply from dehydration to something much more serious such as kidney disease,” said physical therapist Matthew Hyland, president of the New York Physical Therapy Association and co-owner of Rye Physical Therapy & Rehabilitation. “Cramps often result from vigorous exercise, trauma to the muscle, or keeping the leg in an awkward position for too long, such as sitting in a crowded theater.
Other causes can include medications such as birth control, diuretics (which are often prescribed for people with high blood pressure) and steroids. A lack of potassium or calcium can also be the underlying cause, as well as cold weather.”
Acute leg cramps frequently are confused with restless legs syndrome (RLS). But RLS is a different and more serious, chronic condition characterized by discomfort and persistent throbbing and pulling sensations in the legs.
In some cases, the cramps may be a symptom of another problem. For example:
- Some medicines can cause cramps as a side-effect, or make cramps occur more often. These include: thiazide diuretics and loop diuretics (water tablets), nifedipine, cimetidine, salbutamol, statins, terbutaline, lithium, penicillamine and phenothiazines (prochlorperazine, perphenazine, chlorpromazine).
- Over-exertion of muscles.
- 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 kidney (renal) dialysis get leg cramps.
- Pregnancy – usually in the later stages.
- An untreated underactive thyroid gland.
- Peripheral arterial 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 of unknown cause (idiopathic) 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.
How to Prevent Leg Cramps
There are a number ways you can alleviate nighttime leg cramps. “Once leg cramps set in, the best method to relieve them is movement, either walking around or simply jiggling or shaking your leg,” advised Hyland. “In addition, things like pumping your ankles up and down or rubbing the muscles can help as well.”
Some people with chronic leg cramps have found relief using cool compresses, which work by numbing pain and reducing soreness. But Hyland said anyone who regularly suffers leg cramps should also work to strengthen their muscles, which will make cramps less frequent.
“Our musculoskeletal system hits its peak at the age of 20, and while it maintains its peak for an additional 20 years, the reality is that it begins to break down at age 40,” he said. “This includes muscles becoming less flexible. Once we pass into the fourth decade of life, it is critical we play an active role in stretching and strengthening our bodies to maintain appropriate, maximal health.” He added that it may be best to consult a physician if leg cramps last for 5 to 10 minutes or occur multiple times a week.
What to Take for Muscle Cramps
Analgesic balm or a patch, both sold over-the-counter at pharmacies, can provide further relief. OTC pain relief medications that are formulated to treat menstrual cramps, such a Pamprin and Midol, can be an effective treatment for bad leg cramps.
You may also be able to prevent or alleviate muscle cramps in your legs by making simple lifestyle changes. Drinking plenty of water is essential, since cramps are often caused by dehydration. A healthy diet with plenty of fresh fruits and vegetables can also help to decrease the frequency of leg cramps.
Vitamins and Minerals: Potassium and Magnesium for Muscle Cramps
Additionally, certain vitamins and minerals impact muscle function, particularly potassium and magnesium. A significant body of research has found that increasing your magnesium intake can help with the frequency of night time leg cramps, especially for pregnant women.
Health experts recommend getting at least 300 milligrams of magnesium each day. A supplement can help you reach your daily allowance, but so can eating foods rich in magnesium, such as nuts, lentils, and quinoa.
Things to remember
- A muscle cramp is an uncontrollable and painful spasm of a muscle.
- The exact cause is unknown, but some of the risk factors may include poor physical condition, dehydration and muscle fatigue.
- You can help reduce the duration and severity of cramp by gently stretching the muscle and massaging the area.
- See your doctor if you experience regular muscle cramping or if cramps last longer than a few minutes.