A neurologist explains why some muscle twitching is visible and if there’s a difference between ones you can see and hidden fasciculations.

Have you been wondering if being able to SEE a muscle twitching has a specific meaning, versus not being able to see the twitching that you can so easily feel?

“A trap you don’t want to fall into is excessive worry simply because you can see a muscle twitch,” says Anthony P. Geraci, MD, Founder and Director of neurOasis Neurology, Clinical Assistant Professor of Neurology, NYU School of Medicine.

“That just means that the twitch is near the surface, and the skin just above the muscle moves when the muscle fiber contracts,” says Dr. Geraci. Translation: You probably have low body fat! This makes things more visible (e.g., veins in the forearms, “definition”).

Dr. Geraci continues, “These occur throughout the entire muscle in a random fashion and actually, you are having several-fold the number of twitches you actually see – you just aren’t aware of them!

“Seeing a muscle twitch rather than feeling one has no meaning at all and is no cause for concern.”

What about a visible twitch that’s like half a foot long?

I myself once had an elongated visible muscle twitch. After I did a set of pull-ups, a thumping fasciculation developed in my chest. Though the chest is not a primary mover in a pull-up, it isometrically contracts during the movement.

At the gym, I could easily see the twitching in a mirror. It was a horizontal fascic about five inches long! It was “flashing” beneath my chest muscle, right under the clavicle bone. This visible muscle twitching persisted all day long and evening, but was completely gone come next morning.

It really is true: What you can see won’t hurt you.