Muscle cramps

Alternative names
Cramps - muscle


Muscle cramps are involuntary and often painful contractions of the muscles which produce a hard, bulging muscle.

Muscle twitching (fasciculation) is the result of spontaneous local muscle contractions that are involuntary. Typically, these contractions only affect individual muscle groups connected to (innervated by) a particular motor neuron. This twitching does not cause pain.

Ordinary muscle cramps are common and may be stopped by stretching the affected muscle.

Muscle twitches are minor and often go unnoticed. Some are common and normal, while others indicate a neurologic disorder.

Common Causes
Muscle spasms can cause cramps and are usually brought on by the following:

  • Muscle fatigue  
  • Heavy exercise  
  • Dehydration  
  • Pregnancy  
  • Hypothyroidism  
  • Depleted magnesium or calcium stores or other metabolic abnormalities  
  • Alcoholism  
  • Kidney failure leading to uremia  
  • Medications

Muscle twitching may lead to cramping and may involve the following:

  • Benign, nonpathologic fasciculations (not caused by disease or disorders)       o Often affecting the eyelids, calf or thumb       o Commonly triggered by stress, anxiety  
  • Diet deficiency  
  • Side effects of drugs, especially diuretics or caffeine

More serious causes of fasciculations - such as motor neuron disease, muscle diseases, or denervation - are usually accompanied by weakness and atrophy of the affected muscle group, as well as other signs and symptoms.

Home Care
Slow stretching often brings relief. Follow prescribed therapy.

Call your health care provider if

  • There are severe, prolonged or recurring muscle spasms or cramps that aren’t relieved by simple stretching  
  • There are prolonged or persistent muscle twitches that are unexplained, especially if they are accompanied by weakness or muscle wasting

What to expect at your health care provider’s office

Your health care provider will obtain your medical history and will perform a physical examination.

Medical history questions documenting your muscle spasms may include the following:

  • When did the spasms first begin?  
  • How long do they last?  
  • How often do you experience muscle spasms?  
  • What muscles are affected?  
  • Is it always the same location?  
  • Are you pregnant?  
  • Have you been Vomiting, had diarrhea, excessive sweating, excessive urine volume or other possible cause of dehydration?  
  • What medications do you take?  
  • Have you been exercising heavily?  
  • Have you been drinking alcohol heavily?

Diagnostic tests that may be performed include:

  • Blood tests for disorders of the following:       o Calcium, potassium, or magnesium metabolism       o Thyroid function       o Kidney function  
  • Pregnancy test  
  • Electromyography  
  • Myelography

Pain relievers (analgesics) may be prescribed. Job, school and home lifestyle, as well as the role of alcohol use, may be explored.

Johns Hopkins patient information

Last revised: December 8, 2012
by Brenda A. Kuper, M.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.