Muscle twitches are fine movements of a small area of muscle.
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.
Deep anterior muscles
Causes of Muscle Twitching
- Autoimmune disorders such as Isaac syndrome
- Drug overdose (caffeine, amphetamines, or other stimulants)
- Drug side effect (such as from diuretics, corticosteroids, or estrogens)
- Lack of nutrients in the diet (deficiency)
- 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)
Home Care for Muscle Twitching
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 chemistry CT scan of the spine or brain
- Electromyogram (EMG)
- Nerve conduction studies
- MRI scan of the spine or brain
Muscle fasciculation; Fasciculations of muscle