Most of the time, night leg cramps occur for no known reason, and they're usually harmless. 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 experiencing night leg cramps.

In rare situations, night leg cramps can be associated with an underlying disorder, such as peripheral artery disease — in which narrowed arteries reduce blood flow to your limbs — diabetes or spinal stenosis.

Some drugs, particularly intravenous iron, estrogens and naproxen, have been linked to night leg cramps.

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, but RLS could be the cause of night leg cramps.

Other conditions that may sometimes be associated with night leg cramps may include:

Structural disorders

  1. Peripheral artery disease
  2. Spinal stenosis

Medications and procedures

  1. Blood pressure drugs
  2. Diuretics
  3. Oral contraceptives
  4. Cholesterol-lowering drugs (statins)
  5. Dialysis

Other conditions

  1. Dehydration
  2. Diarrhea
  3. Muscle fatigue
  4. Nerve damage, as from cancer treatments
  5. Osteoarthritis
  6. Parkinson's disease
  7. Pregnancy

Metabolic problems

  1. Addison's disease (adrenal insufficiency)
  2. Cirrhosis
  3. Hyperthyroidism (overactive thyroid)
  4. Hypothyroidism (a thyroid disorder)
  5. Chronic kidney disease
  6. Type 1 diabetes
  7. Type 2 diabetes

Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.

Feb. 20, 2013