Muscle twitching

Considerations

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

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

Causes

• Autoimmune disorders such as Isaac syndrome
• Drug overdose (caffeine, amphetamines, or other stimulants)
• Drug side effect (such as from diuretics, corticosteroids, or estrogens)
• Exercise
• Lack of nutrients in the diet (deficiency)
• Stress
• 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 of a nervous system disorder include:

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

Home Care

No treatment is usually needed for benign muscle twitching.

When to Contact a Medical Professional

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

What to Expect at Your Office Visit

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?

Tests depend on the suspected cause, and may include:

• Blood tests to look for problems with electrolytes, thyroid gland function, and blood chemistryCT scan of the spine or brain
• Electromyogram (EMG)
• Nerve conduction studies
• MRI scan of the spine or brain

Alternative Names

Muscle fasciculation; Fasciculations of muscle

References

Chinnery PF. Muscle diseases. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011: chap 429.

Griggs RC, Jozefowicz RF, Aminoff MJ. Approach to the patient with neurologic disease. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011: chap 403.

Update Date: 2/5/2012

Updated by: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Luc Jasmin, MD, PhD, Department of Neurosurgery at Cedars-Sinai Medical Center, Los Angeles, and Department of Anatomy at UCSF, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.