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.

Causes

The specific cause of nocturnal leg cramps is unknown. These cramps may be related to imbalances in local muscle chemistry. This can be related to problems with nerves, muscles, or blood supply.

Risk Factors

Nocturnal leg cramps are more common in people aged 50 years and older. Other factors that may increase your chance of nocturnal leg cramps include:

• Overexertion of muscles
• Prolonged sitting, or standing on hard surfaces
• Pregnancy
• Flat feet, or other foot or ankle deformities
• Alcoholism
• Neurological conditions, such as Parkinson’s disease
• Certain medications, such as those to treat high blood pressure, high cholesterol, or psychiatric disorders
• Certain medical conditions:
  • Hormone disorders such as thyroid disorders or diabetes
  • Dehydration
  • 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. This may include treatment for any underlying causes of the nocturnal leg cramps.

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

Prevention

To help reduce your chance of nocturnal leg cramps:

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

Ortho Info—American Academy of Orthopaedic Surgeons http://www.orthoinfo.org

Women’s Health Matters http://www.womenshealthmatters.ca

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Garrison SR, et al. The effect of magnesium infusion on rest cramps: Randomized controlled trial. J Gerontol A Biol Sci Med Sci. 2011;66(6):661-666.

Nocturnal leg cramps. EBSCO DynaMed website. Available at:
http://www.ebscohost.com/dynamed
Updated January 7, 2013. Accessed December 16, 2013.

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El-Tawil S, Musa T, et al. Quinine for muscle cramps. Cochrane Database Syst Rev. 2010;(12):CD005044.