Definition

Nocturnal leg cramps are sudden contractions of the lower leg and foot muscles. They often awaken you from sleep. The calf muscles are most often involved.

The Calf Muscles

Nucleus factsheet image

Copyright © Nucleus Medical Media, Inc.

Causes

The specific cause of nocturnal leg cramps is unknown. These cramps may be related to imbalances in local muscle chemistry. Many activities and diseases are associated with nocturnal leg cramps including:

    
  • Overexertion of the muscles
  • Prolonged standing on hard surfaces
  • Prolonged sitting
  • Dehydration
  • Diseases:    
  • Diabetes
  • Parkinson's disease
  • Hormone disorders such as thyroid disorders
  • Chemical imbalances in calcium, potassium, magnesium, and others
  • Certain medications:    
  • Blood pressure medications
  • Statins taken to lower cholesterol
  • Morphine
  • Lithium
  • Risk Factors

    Those over 50 are at increased risk for leg cramps. The following factors also increase your chance of developing nocturnal leg cramps:

        
  • Overexertion
  • Pregnancy
  • Staying in certain positions for a long time
  • Flat feet or other foot or ankle deformities
  • Alcoholism
  • Neurologic diseases
  • Certain medications
  • Diabetes
  • Parkinson's disease
  • Hypoglycemia
  • Hormone disorders such as thyroid disorders
  • Chemical imbalances in calcium, potassium, magnesium, and others
  • Symptoms

    The main symptom is sudden calf or foot cramps.

    Diagnosis

    You will be asked about your symptoms and medical history. A physical exam will be done.

    Your bodily fluids may be tested. This can be done with blood tests.

    Treatment

    Talk with your doctor about the best plan for you. If no specific cause can be found, treatment options include the following:

        
  • When cramps occur, stretch your leg muscles.
  • Standing on the affected leg and walking often stops the cramping.
  • Massage and hot or cold treatments help the muscles relax.
  • Medications

    No medication has proven to treat nocturnal leg cramps. Quinine, while often effective for reducing the frequency and intensity of cramps, has a significant risk of major allergic reactions. The other prescription medications carry risks as well. So, they are not generally recommended. They may be used in severe cases.

    Prescription

        
  • Quinine sulfate
  • Muscle relaxants
  • Calcium channel blockers
  • Anticonvulsants
  • Prevention

    To reduce your chance of getting nocturnal leg cramps, take the following steps:

        
  • Stretch during the day and just before going to bed.
  • Exercise feet and legs regularly.
  • Drink plenty of liquids.
  • Wear comfortable, supportive shoes.