Definition
Night leg cramps happen when leg muscles suddenly tighten during sleep. They’re also called nocturnal leg cramps. Night leg cramps usually involve calf muscles, although muscles in the feet or thighs might cramp as well. Stretching the tight muscle with force can relieve the pain.
Causes
Most of the time, there’s no known cause for night leg cramps. In general, they’re likely the result of tired muscles and nerve problems.
The risk of having night leg cramps increases with age. Pregnant people also are more likely to have night leg cramps.
Kidney failure, diabetic nerve damage and problems with blood flow are known to cause night leg cramps. But if you have one of these conditions, you probably already know. And you likely have symptoms other than just night leg cramps.
People who take medicines that increase urine output might be more likely to have night leg cramps. But it’s not known if there’s a direct link.
Restless legs syndrome is sometimes confused with night leg cramps. But the conditions are different. The most common symptom of restless legs syndrome is the need to move the legs when falling asleep. Restless legs syndrome is usually not painful, and the symptoms last longer than do night leg cramps.
Other health issues that can sometimes be linked to night leg cramps include:
Acute kidney injury
Addison’s disease (adrenal insufficiency)
Alcohol use disorder
Anemia — a condition in which the body doesn’t get oxygen due to a lack of healthy red blood cells.
Chronic kidney disease
Cirrhosis (scarring of the liver)
Dehydration (when the body doesn’t have enough water and other fluids to work as it should)
Dialysis
High blood pressure (hypertension)
Hyperthyroidism (overactive thyroid)
Hypoglycemia
Hypothyroidism (underactive thyroid)
Lack of physical activity
Medicines, such as those used to treat blood pressure problems and high cholesterol, and birth control pills
Muscle fatigue
Parkinson’s disease
Peripheral artery disease (PAD)
Peripheral neuropathy
Pregnancy
Spinal stenosis
Type 1 diabetes
Type 2 diabetes
