Leg cramps are involuntary, temporary muscle contractions in the legs that are often painful. They can affect the whole muscle or certain bundles. They are mostly benign but are quite debilitating because you cannot use the muscle during the cramp. They appear suddenly and usually last between a few seconds to a few minutes. Sometimes you might have “residual” pain for a few days after a cramp.

They can occur during warm-up, during exertion, and even at rest. They can strike at any time of the day or night, whether you are lying down or running a jog. Characterized by intense and localized pain in the leg muscles, such as a contraction, they are one of the most painful cramps you may experience. 

Let’s see together what the cause of your leg cramps could be.

Cramps (and leg cramps) are barely understood

The exact mechanism of cramps is still not understood by medicine. We know that it is due to nervous problems and muscle fatigue as much as to an imbalance in the movement of electrolytes within cells (the electrolytes are calcium, magnesium, potassium, and sodium, which regulate exchanges in cells).

Statistically, it has been observed that many diseases and health conditions are associated with more frequent cramps: cancer treatment, heart disease, liver disease, kidney dialysis, hypothyroidism, arthritis, diabetes, venous insufficiency, and pregnancy. Many medicines can also trigger cramps, including statins, birth control pills, naproxen, diuretics, antipsychotics, and cortisone.

In general, all the problems slowing the circulation of the muscles increase the risk of cramps: this can be drugs that eliminate or block the action of nutrients, but also dehydration or the simple fact of staying still for too long, for example sitting cross-legged.

People with venous insufficiency are, of course, more likely to get cramps, as are people with diabetes, whose small blood vessels (capillaries) are damaged and provide poor blood supply to the organs.

Likely causes of leg cramps


The “classic” cause of leg cramps is a lack of hydration. The exact mechanism is not yet well understood by scientists, but the lack of fluids may cause sensitization of nerve endings, causing contractions around the nerve. Heat or exercise can therefore increase the risk of leg cramps since sweating increases the body’s dehydration.

Mineral deficiency

Perspiration is not only made up of water, but it also contains electrolytes, minerals essential to our functioning. In the case of sodium, calcium, magnesium, or potassium deficiency, this imbalance can cause cramps. The risk can be reduced with electrolyte drinks as well as a balanced diet. 

You can eat bananas, sweet potatoes, spinach, yogurt, and nuts, which are rich in minerals, before and after your workouts to avoid cramps.

Excessive exercise

If you haven’t been active in a sport for a long time and start too hard, you may trigger leg cramps. This is often due to the nerves being overstimulated. Resting and stretching is especially important in this kind of situation. 

Sitting or standing for too long

Muscles love to contract and rest, they are made to move. So, if you spend the day standing in a line, you might strain your leg muscles and experience a cramp. In this case, try to move a bit. 

Sitting for too long also has the same consequence. Improperly positioned, the muscle cannot relax and ends up contracting into a cramp. By making sure to walk a few minutes for every hour you spend sitting down, you should prevent this painful situation.


If you can’t think of a reason for your leg cramps (or camps in general), take a look at your medication kit. Diuretic medicines can cause a decrease in mineral salts in the body, which can cause cramps. Other drugs like statins are also associated with this problem. If you have repeated cramps, talk to your doctor to find an alternative treatment, as well as to rule out other possible underlying causes related to diseases.

High blood pressure

High blood pressure can have many causes. The most common are stress, a diet too rich in salt, and too little exercise. These conditions can also cause your body to cramp. So, try to avoid that. Also, have your blood pressure regularly measured if you suffer from high blood pressure, and make sure to get plenty of physical activity along with a healthy diet.

Cold temperatures

Cold temperatures can cause your leg muscles to cramp. Cramps are a muscular contracture and cold temperatures risk amplifying the muscular contraction because it decreases vascularization. To avoid cramps during the colder seasons, make sure you wear appropriate clothing and avoid stay still for too long.

Low blood sugar levels

Low blood sugar levels can also cause muscle cramps. Fortunately, you can quickly remedy this, for example by eating a piece of dark chocolate. A piece of fruit, such as an apple, can also help your blood sugar level up.


More than half of pregnant women have leg cramps. Some women also have muscle cramps in the buttocks or thighs. Cramps often occur at night, especially during the 2nd and 3rd trimesters.

Cramps during pregnancy can have different causes, some of which we have already mentioned:

  • The increased weight of the uterus, which increases the pressure on the abdominal nerves and blood vessels;
  • Tiredness;
  • An imbalance of minerals in the blood or a vitamin deficiency. For example, a lack of calcium, phosphorus, vitamin D, or vitamin E could cause cramps;
  • Dehydration;
  • Inactivity or over-exercising;
  • Poor blood circulation caused by increased blood volume and the pressure of the uterus on the blood vessels;
  • Twitching your toes.

How to prevent leg cramps

  • Pay attention to diet: Your muscles need energy to function properly. Make sure you eat a balanced and varied diet with plenty of fruits and vegetables. Ensure adequate intake of calcium, potassium, sodium, glucose, and magnesium.
  • Stop smoking: Smoking can cause painful muscle cramps.
  • Drink enough water: Drink at least 1.5 liters per day. If you are going to exercise, drink an extra half a liter of water in advance. For every 45 minutes of exercise, your body needs an extra half a liter of water. Dehydration increases the risk of cramps.
  • Avoid strenuous physical activity: If you are just starting a new sport, avoid going too hard at it. Build up your level slowly and make sure you take appropriate breaks. Start with a warm-up for your muscles and end with a cool-down. A slight stretching between exercises will also relax your muscles. Give your muscles some breathing space after exercise and give your body a few days of rest.
  • Wear adapted sportswear: A good pair of sports pants that keeps your muscles warm longer will help prevent muscle cramps.
  • Stretch: You can prevent nightly muscle cramps in, for example, your calf or toes by stretching quietly before you go to bed.

To remember

  • Cramps are caused by an involuntary contraction of the muscles in the leg.
  • Eating a balanced diet, staying hydrated, and exercising can help prevent cramps.
  • Calf stretches can relieve pain when a cramp occurs.
Stephan Meed

A southern gentleman at heart, Stephan is a man you'll find mudding, off-roading, and fishing on a typical weekend. However, a nutritionist by profession, he is also passionate about fitness and health through natural means. He writes mostly health-related content for the Scientific Origin.