Muscle twitching

Definition

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

Alternative Names

Muscle fasciculation; Fasciculations of muscle

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.

Common 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.

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?

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 scanof the spine or brain

Prevention

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.