Muscle twitching

• Alternative Names

  Muscle fasciculation; Fasciculations of muscle

• Considerations

  Muscle twitching is caused by minor muscle contractions in the area, or the uncontrollable twitching of a muscle group that is served by a single motor nerve fiber or filament.

  Muscle twitches are minor and often go unnoticed. Some are common and normal. Others are signs of a nervous system disorder.

• Common Causes
  • Diet deficiency
  • Drug overdose (caffeine)
  • Drug side effect (such as from diuretics, corticosteroids, or estrogens)
  • Exercise
  • Twitches not caused by disease or disorders (benign twitches)
    • Often affecting the eyelids, calf, or thumb
    • Normal and quite common, often triggered by stress or anxiety
    • Come and go, and do not last for more than a few days

  Nervous system conditions that can cause muscle twitching:

  • Amyotrophic lateral sclerosis (ALS - Lou Gehrig's disease)
  • Damage to the nerve that leads to a muscle
  • Muscular dystrophy
  • Spinal muscular atrophy
  • Weak muscles (myopathy)

  Symptoms that suggest a nervous system disorder include:

  • Loss of, or change in sensation
  • Loss of muscle size (wasting)
  • Weakness
• Home Care

  There is usually no treatment necessary for benign muscle twitching.

• Call your health care provider if

  Call your health care provider if you have long-term or persistent muscle twitches.

• What to expect at your health care provider's office

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

  Medical history questions 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 in the same location?
  • Are you pregnant?
  • What other symptoms do you have?

  Diagnostic tests vary depending on the suspected cause. Tests may include:

  • Blood tests to look for problems with electrolytes, thyroid gland function, and blood chemistry
  • Electromyogram
  • Nerve conduction studies
  • MRI of the spine, and sometimes of the brain
• References

  Barohn RJ. Muscle diseases. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 447.

Review Date: 11/13/2008

Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.