This article is about the causes of intermittent muscle twitching (fasciculations), not spasms.

Intermittent muscle twitching (fasciculations) is not the same phenomenon as spasms.

If you’re wondering what can be causing intermittent twitching of your muscles, here is what Dr. Anthony P. Geraci, a neurologist, says:

“This is a short answer: Benign muscle twitches are due to unstable muscle fiber membranes, usually due to injury (as when we work out).  The twitching is simply a random phenomenon.”

Dr. Geraci is associate professor of neurology at Donald & Barbara Zucker School of Medicine in New York.

Thus, the intermittency, in and of itself, is no cause for concern.

And don’t let the term “injury” scare you.

Every time you exercise, you injure muscle fiber membranes. They then repair themselves, and this is one way that exercise makes you stronger.

This injury is especially caused from intense weightlifting.

Benign fasciculations come in all sorts of flavors, shapes and colors, in that they can be occasional, intermittent for a few days or weeks, intermittent for many months, ongoing for a few days, and even ongoing for much longer periods of time.

Benign fascics can also occur in response to specific activities such as hiking, using the revolving staircase, chin-ups or bench pressing.

Thus, their occurrence is contingent on how often you do these triggering activities.

Other benign causes of common muscle twitching are fatigue, emotional stress and mineral deficiencies.

If you have fasciculations and no noticeable weakness or other concerning symptoms like slurred speech, chances are pretty high that you do not have a neurological disease (i.e., despite the fascics, you can still knock off pushups, run up and down stairs, be on your feet all day at work without a hitch, etc.).

Note, however, that “benign fasciculation syndrome” typically comes with some cramping and/or exercise intolerance, though it is not progressive.

Dr. Geraci is also the director of neuromuscular medicine at Northwell Health in New York.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  


Top image: ©Lorra Garrick