Night leg cramps happen when leg muscles suddenly tighten during sleep. These cramps also are 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.
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 issues.
The risk of having night leg cramps increases with age. People who are pregnant also are more likely to have night leg cramps.
Kidney failure, diabetic nerve damage and issues with blood flow are known to cause night leg cramps. But if you have one of these conditions, you probably already know. And you are likely to 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 night leg cramps do.
Other health issues can sometimes be linked to night leg cramps.
Common causes
- Dialysis
- Dehydration
- Lack of physical activity
- Medicines, such as birth control pills and those used to treat blood pressure and high cholesterol
- Muscle fatigue
- Pregnancy
Endocrine and metabolic conditions
- Addison's disease
- Anemia — a condition in which the body doesn't get oxygen due to a lack of healthy red blood cells
- Chronic kidney disease
- Hyperthyroidism (overactive thyroid)
- Hypoglycemia
- Hypothyroidism (underactive thyroid)
- Type 1 diabetes
- Type 2 diabetes
Neurologic conditions
Vascular conditions
Other medical conditions
For most people, night leg cramps are just a bother that sometimes wakes them with a jolt. But some people who have night leg cramps might need to see a healthcare professional.
Seek medical care right away if you have:
- Severe cramping that continues.
- Night leg cramps after coming into contact with a toxin, such as pesticide, industrial chemicals or heavy metals.
Schedule an office visit if you:
- Are tired during the day because leg cramps interrupt your sleep.
- Have muscle weakness and loss of muscle mass with leg cramps.
Self-care
To help prevent night leg cramps, try to:
- Drink plenty of fluids, but limit alcohol and caffeine.
- Stretch leg muscles or ride a stationary bicycle for a few minutes before bedtime.
- Loosen the sheets and covers at the foot of the bed.
To relieve night leg cramps, try to:
- Stretch the leg and flex the foot up toward the face.
- Massage the muscle with ice.
- Walk or shake the leg.
- Take a hot shower and point the water at the cramped muscle, or soak in a warm bath.
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