What causes muscle twitching? And here's when you should worry.

Though many people experience muscle twitching, it's often incorrectly identified as a muscle spasm. While both are involuntary contractions of a muscle, muscle spasms and muscle twitching aren't actually the same thing. A muscle twitch is a short contraction that sometimes occurs repeatedly − think eye twitching. Such movement can be uncomfortable and inconvenient, but it isn't usually painful. Muscle spasms, on the other hand, are prolonged muscle contractions that are often painful. 

In many cases, the same practices that prevent or end muscle spasms can also prevent or end muscle twitches − though experts say it isn't possible for most people to avoid either completely. 

What causes muscle twitching?

Our body's nervous system is constantly telling our muscles what to do without our having to consciously thinking about each action. Such messages are controlled by our central nervous system (brain and spinal cord) and by the peripheral nervous system or PNS. The PNS is the part of our nervous system that feeds information into our brain and carries the signals that move our muscles, per Cleveland Clinic. 

Because these nerves are constantly triggering muscle movements day after day, they can be very sensitive and sometimes misfire. "Almost always this is due to motor nerves that send signals from the spine or brain to the receptors," explains Loren Fishman, MD, a professor of physical medicine and rehabilitation at Columbia University.

He says that various factors can interfere with how these brain signals are sent to different muscle groups which can sometimes lead to "involuntary" twitching. Some such factors and others include dehydration, stress, medication, caffeine, a pinched nerve, damaged nerve cells or lack of sleep. More rarely, muscle twitching can be affected by medical conditions such as Serotonin syndrome, Lou Gehrig's Disease, Isaacs' syndrome or kidney disease.

Fishman says twitching can also be connected to an anxiety disorder or as a result of a nutritional deficiency. "Twitching can occur when your basic electrolytes such as sodium, potassium, magnesium, calcium are abnormally high or low," adds Fishman. 

Anthony Beutler, MD, an associate medical director of sports medicine at Intermountain Health in Salt Lake City, says it can be helpful to think of some such factors or conditions as causing "short circuits in the muscle’s nervous system." 

How do I stop my muscles from twitching?

Because such muscle responses aren't voluntary, it can be difficult to predict when twitching will occur or to prevent it from happening altogether. Beutler says that "there is no single or foolproof way to stop twitches," but offers a few recommendations that have proven to can be helpful. These include stretching one's muscles, engaging in exercises that contract affected muscle groups or medications recommended by a healthcare professional. 

Fishman says that maintaining a healthy diet and drinking plenty of water can also help one naturally get enough electrolytes to prevent or ease symptoms of muscle twitching. "Activities that lightly use and soothe the muscles and cause your emotions to relax can also be helpful," he adds. Such activities may include yoga, walking or meditation. 

When should I worry about muscle twitching? 

Knowing when muscle twitching is a problem can be difficult to ascertain since many things can contribute to it happening. Fortunately, it's rarely serious, often passes on its own, and usually not connected to chronic health conditions. Therefore, under most circumstances, the experts say muscle twitching isn't something to be overly concerned about. 

But if twitching persists, spreads or gets progressively worse over time, Beutler advises to make an appointment with your primary care physician to assess your symptoms and rule out anything worrisome. 

Muscle spasms are inconvenient, painful:Here's how to avoid them.