Muscle fasciculation

Alternative names
Muscle twitching; Fasciculations of muscle

Muscle twitches are fine movements of a small area of muscle.

Muscle twitching is the result of minor local muscle contractions or the uncontrollable twitching of a single muscle group served by a single motor nerve fiber or filament.

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

Common Causes

  • Benign twitches (not caused by disease or disorders)       o Often affect the eyelids, calf, or thumb       o Normal and quite common, often triggered by stress or anxiety  
  • A diet deficiency  
  • Drug overdose  
  • Drug side effect (such as diuretics, corticosteroids and estrogens)  
  • Exercise

Symptoms suggestive of a neurological cause of fasciculations include:

  • Wasting of muscle  
  • Weakness  
  • Other findings of nerve dysfunction

Neurological illnesses where fasciculations are seen include:

  • Chronic denervation of muscle due to disc compression of nerve exiting the spinal cord  
  • ALS (Lou Gehrig’s Disease)  
  • Spinal muscular atrophy  
  • Muscular dystrophy  
  • Myopathy

Home Care
There is usually no treatment necessary.

Call your health care provider if

Call your health care provider if you have prolonged or persistent muscle twitches.

What to expect at your health care provider’s office
The medical history will be obtained and a physical examination performed.

Medical history questions documenting your fasciculations in detail may include:

  • When did you first notice the twitching?  
  • How long does it last?  
  • How often do you experience twitching?  
  • What muscles are affected?  
  • Is it always the same location?  
  • Are you pregnant?  
  • What other symptoms are also present?

DIAGNOSTIC TESTS vary depending on the suspected cause. There is often no need to treat this symptom.


If a condition was diagnosed related to muscle twitches, you may want to note this in your personal medical record.

Johns Hopkins patient information

Last revised: December 5, 2012
by Potos A. Aagen, 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.