Night cramps (also called nocturnal leg cramps) are sudden, painful muscle contractions that usually affect the calves or feet during sleep. They are common and often have no clear cause, but some people are at higher risk.
People most at risk
- Older adults
The risk increases with age, possibly because of changes in muscle and nerve function. - Pregnant women
Night cramps are common, especially during the second and third trimesters. - People who stand or sit for long periods
Jobs or activities that involve prolonged standing or sitting may increase the likelihood of cramps. - People who exercise intensely
Muscle fatigue from vigorous exercise can contribute to nighttime cramping. - People who are dehydrated
Not drinking enough fluids, especially during hot weather or after exercise, may increase the risk in some individuals. - People with certain medical conditions
Night cramps are more common in people with conditions such as:- Diabetes
- Peripheral artery disease
- Chronic kidney disease
- Some nerve disorders
- People taking certain medications
Some medicines have been associated with muscle cramps in some people, including certain:- Diuretics (“water pills”)
- Cholesterol-lowering medications (although the relationship varies)
- Other medications in selected cases
What may help prevent them
- Stay well hydrated.
- Stretch your calf muscles before bed.
- Stay physically active, but avoid sudden increases in exercise intensity.
- Wear supportive footwear during the day if you’re on your feet a lot.
- Talk to your healthcare provider if cramps begin after starting a new medication.
When to see a doctor
Seek medical evaluation if your cramps:
- Are frequent or severe.
- Cause persistent muscle weakness.
- Are associated with swelling, redness, or numbness.
- Significantly disrupt your sleep.
Bottom line
Night cramps are most common in older adults, pregnant women, and people with certain medical conditions or medication use. Occasional cramps are usually harmless, but frequent or severe episodes deserve medical evaluation to look for an underlying cause.
