MedlinePlus Medical Encyclopedia: Muscle cramps

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Muscle cramps

Contents of this page:
Illustrations Alternative names Definition Considerations	Common Causes Home Care Call your health care provider if What to expect at your health care provider's office

Illustrations

Alternative names Return to top

Cramps - muscle

Definition Return to top

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.

Considerations Return to top

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 Return to top

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)
- Often affecting the eyelids, calf or thumb
- 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 Return to top

Slow stretching often brings relief. Follow prescribed therapy.

Call your health care provider if Return to top

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 Return to top

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:
- Calcium, potassium, or magnesium metabolism
- Thyroid function
- 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.

Update Date: 8/6/2004

Updated by: Jonathan Harding, MD, CPE, Department of Medicine, University of Massachusetts Medical School, Worcester, MA. Review provided by VeriMed Healthcare Network.

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