Night leg cramps, also called nocturnal leg cramps, are painful, involuntary contractions or spasms of muscles in your legs, usually occurring when you're in bed. Night leg cramps usually involve your calf muscles, although muscles in your feet or thighs might cramp as well. Forcefully stretching the contracted muscle relieves the pain.
he risk of having night leg cramps increases with age. Pregnant women also have a higher likelihood of having night leg cramps.
Several conditions, such as kidney failure and diabetic nerve damage, are known to cause night leg cramps. But if you have one of these, you're most likely aware of it and have symptoms other than night leg cramps.
People who are taking certain medications, such as certain diuretics, might be more likely to have night leg cramps, although it's not known if there's a direct connection.
Restless legs syndrome (RLS) is sometimes confused with night leg cramps, but it's a separate condition. In general, pain is not a main feature of RLS, although some people describe their RLS as being painful.
Other conditions that may sometimes be associated with night leg cramps may include:
Peripheral artery disease
Acute kidney failure
Addison's disease (adrenal insufficiency)
Chronic kidney disease
Cirrhosis (scarring of the liver)
Hyperthyroidism (overactive thyroid)
Hypothyroidism (underactive thyroid)
Type 1 diabetes
Type 2 diabetes