Night cramps (also called nocturnal leg cramps) are sudden, painful muscle contractions that most often affect the calf, foot, or thigh during sleep. They can happen to anyone, but some people are at higher risk.
Those at higher risk include:
- Older adults – Night cramps become more common with age.
- Pregnant women – Especially during the second and third trimesters.
- People who stand or sit for long periods – Muscle fatigue or prolonged positioning may contribute.
- People who exercise intensely – Overuse or muscle fatigue can trigger cramps in some individuals.
- People taking certain medications – Some medications have been associated with muscle cramps as a side effect. If you suspect a medication is contributing, discuss it with your healthcare provider before making any changes.
- People with certain medical conditions, including:
- Peripheral artery disease
- Diabetes
- Chronic kidney disease
- Some neurological disorders, such as Parkinson disease
Can dehydration or low minerals cause cramps?
It’s a common belief that dehydration or low levels of minerals like magnesium or potassium are the main cause of night cramps. In reality, for most otherwise healthy adults with nocturnal leg cramps, the evidence for these being the primary cause is limited. However, they can contribute in some situations, particularly after heavy sweating, illness, or with certain medical conditions.
What may help prevent them
- Stretch your calf and hamstring muscles before bed.
- Stay physically active without overexerting yourself.
- Drink enough fluids, especially after exercise or in hot weather.
- Wear supportive footwear if you’re on your feet a lot.
When to see a healthcare professional
Seek medical advice if your cramps:
- Are frequent or very painful.
- Cause persistent muscle weakness.
- Are accompanied by swelling, redness, or numbness.
- Begin after starting a new medication.
- Significantly disrupt your sleep despite self-care.
Occasional night cramps are common and usually not a sign of a serious problem, but recurrent or severe episodes are worth discussing with a healthcare professional to look for an underlying cause.
