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

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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
  • 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.

    Other medications have may be used in severe cases. These may include:

        
  • Muscle relaxants
  • Calcium channel blockers
  • Anticonvulsants
  • 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