Causes

Most of the time, no apparent cause for night leg cramps can be identified. In general, night leg cramps are likely to be related to muscle fatigue and nerve problems.

The 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:

Structural disorders

• Peripheral artery disease (PAD)
• Spinal stenosis

Metabolic problems

• Acute kidney failure
• Addison's disease (adrenal insufficiency)
• Anemia
• Chronic kidney disease
• Cirrhosis (scarring of the liver)
• Hyperthyroidism (overactive thyroid)
• Hypothyroidism (underactive thyroid)
• Type 1 diabetes
• Type 2 diabetes

Medications and procedures

• Blood pressure drugs
• Cholesterol-lowering drugs (statins)
• Dialysis
• Diuretics (water retention relievers)
• Oral contraceptives

Other conditions

• Dehydration
• Diarrhea
• Muscle fatigue
• Nerve damage, as from cancer treatments
• Osteoarthritis (disease causing the breakdown of joints)
• Parkinson's disease
• Pregnancy