What Causes Leg Cramps?

When it comes to describing what causes leg cramps, a range of factors can come into play, underpinning this fairly common problem.

what causes leg cramps

What causes leg cramps? A variety of conditions, from dehydration to diet. Measures you can take to prevent them: Keep your calf muscles limber with stretching exercises; stay hydrated massage; and maintain a balanced diet.

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Up to 60 percent of Americans suffer from leg cramps—with women and older adults particularly susceptible—and about 4 million people age 65 and older report the problem. What causes leg cramps? Dehydration is often cited as a major factor, but numerous other reasons may contribute to cramps:

  • Excess alcohol consumption
  • Medical conditions such as diabetes, thyroid disease, peripheral artery disease (especially if leg cramps develop while you are walking), peripheral neuropathy (especially if you suffer from diabetes, lupus, or rheumatoid arthritis), and cirrhosis
  • Muscle fatigue
  • Spinal stenosis
  • Pregnancy
  • Decreased potassium levels (as with hyperkalemia, which can occur in people taking medications for high blood pressure)
  • Certain medications, including cholesterol-lowering statins, calcium channel blockers and diuretics (used to treat high blood pressure), and some antipsychotic drugs.

Other theories as to what causes leg cramps include modern life. Some scientists suggest that for those with a sedentary lifestyle, leg cramps may be more common because we no longer use our leg muscles for activities like squatting and stretching.

Could Summer Heat Be What Causes Leg Cramps?

Leg cramps can last up to nine minutes and while the calf muscles are most often affected, the muscles of the feet and thigh also can be subject to cramps. Leg cramps typically occur at night, and they also may be more common in the summer, according to a 2015 study published in the March 3, 2015 issue of the Canadian Medical Association Journal.

The study focused on new prescriptions for quinine (which is prescribed to treat leg cramps in the United Kingdom and Canada and is often used off-label in the U.S.) and compared the number to Google searches for leg cramps. Researchers found that prescriptions for quinine peaked in British Columbia in July, as did Google searches for leg cramps. In Australia, where mid-summer is in January, Google Trends data indicated a similar peak for leg cramp searches. (There was no observed seasonality for search terms for back pain, kidney stones, migraines, acne, or panic attacks.)

“Although there are anecdotal reports of pregnancy-associated rest cramps being worse in summer, these findings establish the phenomenon of seasonality in rest cramps in the general population,” said Scott Garrison, MD, PhD, associate professor with the University of Alberta’s Faculty of Medicine.

Managing Leg Cramps

It’s important that you don’t self-diagnose leg cramp causes, since you may have an underlying condition contributing to the problem. If medications are a factor, speaking to your doctor can also help; he or she can substitute another medication or lower the dosage of the medication you are currently taking to see whether a change helps ease your leg cramps.

While you may be able to pinpoint what causes leg cramps, there is no approved treatment for the condition. However, self-help measures like drinking plenty of water during the day and frequently stretching your calf muscles may help. To stretch your calf muscles, stand an arms’ length away from the wall, with your palms resting on it. Slide your right foot back a few inches, and then bend your left knee. Keep the heel of the right leg flat on the floor to increase the stretch. Repeat with your left foot behind and your right leg bent.

Sleep Tight (But Not Too Tight) and Eat Right

Sleeping with your feet flexed may help prevent leg cramps. Avoid tight bedding, which may confine your feet into a toes-pointed position.

Eating foods rich in potassium, such as bananas, tomatoes, and beans, also may help. If you take medication for high blood pressure, check with your doctor before increasing your potassium intake consumption; some blood pressure medications can cause it to build up in your system).

And keep in mind that during a painful cramp, you can relieve the discomfort by straightening your leg and flexing your foot, and also by massaging the muscle. For additional exercises and natural treatments for easing your leg cramps, click here.

Originally published in 2016, this article is regularly updated.

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Kate Brophy

Kate Brophy is an experienced health writer and editor with a long career in the UK and United States. Kate has been Executive Editor of the Icahn School of Medicine … Read More

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