15 Nervous Habits That Are Bad for Your Health, According to Experts

Pickers, grinders, biters, and pullers beware—these are the side effects of your nervous habits.

We all have a nervous habit. Whether it's tapping your toes or twirling your hair, these behaviors, which can seem almost involuntary, are your body's way of coping with anxiety or stress. "The habit might release tension, fill time, act as a distraction, or even be a sense of pleasure, such as satisfaction," says Michelle G. Paul, PhD, a psychologist and the director of The Practice Mental Health Clinic at the University of Nevada, Las Vegas. In many cases, these habits are relatively innocuous—occasionally picking at a pimple or cracking your knuckles isn't going to have dire consequences on your wellbeing. But it's important to take a step back to assess just how often you engage in your nervous habits, and what long-term effects they could have on your overall health.

To help you identify what may be cause for concern, here are 15 nervous habits that could be bad for your health if you do them too often.

Cracking your knuckles

young woman stretching arms

According to Robert H. Shmerling, MD, a rheumatologist and associate professor in medicine at Harvard Medical School, cracking your knuckles is common not only because it feels good physically, but also because of what it does for you mentally. "It can become a habit or a way to deal with nervous energy; some describe it as a way to release tension," Schmerling wrote in a 2018 article for Harvard Health Publishing. The cracking sound occurs due to gas bubbles in your finger joints collapsing or bursting, and while it's "probably harmless," he notes, cracking your knuckles too often could potentially result in tendon injuries or dislocations.

Cracking your neck

woman holding neck

If you're a neck-cracker, you might want to rethink how often you are engaging in that habit. According to the University of Southern California's Keck Medicine, it's OK to crack your own neck once in a while, but it's better left to the pros. That's because, in rare cases, neck manipulations can lead to serious complications, like a stroke. (A man from Oklahoma made headlines for this very thing in May 2019.) Cracking your neck "places the vertebral artery in a precarious position prone for injury," according to Nura Orra, MD, a family medicine physician and member of the ABC News Medical Unit. "Studies have shown a correlation between increased risk of stroke and people who get their necks manipulated."

Besides, if you're already feeling pain in your neck that's causing you to crack it, chances are you could have an issue that should be addressed by a doctor. It's always better to be safe than sorry when it comes to your body.

Chewing on pens and pencils

man chewing on a pen

If you've ever borrowed a pen or pencil from someone, you know that it's not uncommon to see the imprint of teeth marks on the borrowed writing utensil. While putting your pen in your mouth from time to time isn't cause for alarm, if it becomes habitual, it can be harder to curb down the road. And that's not good news for your teeth or your immune system. "Chewing on pens and pencils can cause potential harm to your teeth," Paul says. "It also exposes you to germs."

Chewing gum

woman blowing gum bubble

Always have a stick of gum on hand, or in mouth, rather? This seemingly safe habit could be doing harm to your health. Aside from potentially causing cavities if the gum contains sugar, the act of chewing could strain your jaw and cause pain, says dental insurance company Delta Dental. Another downside is the impact it can have on your digestive system. According to the National Institutes of Health, the artificial sweetener sorbitol found in many common gum brands is known for causing sometimes-painful gas and bloating.

Biting your nails

man biting his nails

According to the American Academy of Dermatology, nail-biting can damage the skin around your nails, which affects the way they grow, and can increase your chances of infection by passing bacteria and viruses from your mouth to your fingers, and vice versa.

Pulling your hair

Young Black Man Examines Hair Loss

Hair pulling—a habit that, in some cases, is classified as a mental disorder called trichotillomania, according to the Mayo Clinic—can be so overwhelming and severe that a person who engages in the behavior is left with permanent bald spots. "Significant hair pulling can result in damage to the hair follicles so that hair doesn't grow back, which produces patches of baldness," Paul says.

Twirling your hair

woman twirling hair around

Twirling your hair might not sound nearly as harsh as pulling it: It's just something you do while watching TV or reading a book, right? Unfortunately, according to Paul, twisting your hair around your finger over and over again could end up damaging your hair follicles as well. Plus, according to TrichStop, an online community for those with trichotillomania, twirling can easily evolve into pulling, so it's a good idea to put an end to this habit as soon as you can to avoid doing any more unnecessary damage to yourself.

Picking at your skin

popping a pimple

When you have something on your skin—a pimple, callus, or scab, for example—it can be hard not to pick at it. But if you have the urge to pick all the time, you may be dealing with skin picking disorder, or SPD. Mental Health America says the disorder causes people to engage in behavior like picking at completely healthy skin—or picking at minor skin irregularities—for significant amounts of time on a daily basis. "The biggest potential negative health outcome for picking at your skin is increasing the potential for tissue damage, infection, and the spread of infection," Paul says. "There's also the possibility of scarring and disfigurement."

Scratching your skin

man scratching arm

If you have an itch, giving yourself a nice scratch is fine. But, just like skin picking, skin scratching can also be a compulsive behavior that can cause damage. According to the University of Chicago Medical Center, it can lead to skin infections, bleeding, and, in severe cases, may require skin grafts or other forms of surgery to repair the damage it can cause. "If you think about it, when you scratch an itch, it's incredibly rewarding on some level," Jon Grant, MD, an addictive disorders expert, told UChicago Medicine. "But at some point people with this disorder look in the mirror and say, 'What have I done?'"

Or simply touching your face

old man face sagging

How many times a day do you touch your face? It's probably more than you think. While face touching isn't as serious as picking at your face or severely scratching yourself, the repetitive habit can still have negative side effects. According to the American Academy of Dermatology, regularly touching your face can expose it to dirt, oil, bacteria, and viruses, which can trigger acne and increase your risk of infection.

Grinding your teeth

woman grinding teeth in bed

Bruxism is medical term for what we know as teeth grinding, and it often goes hand-in-hand with stress or anxiety, according to the Mayo Clinic. As Paul notes, chronic teeth-grinding behavior can put you at risk for several uncomfortable side effects. "The potential negative health effects of teeth grinding include headaches, earaches, worn-down teeth vulnerable to decay or loss, and disturbed sleep for you or your partner," she explains.

Licking your lips

young white man with beard licking lips

If you find yourself licking your lips throughout the day—especially when you're feeling anxious or stressed—it could be a nervous habit. But even if you're only trying to moisturize your dry lips, it's not the method to use. In fact, licking your lips continuously doesn't keep them moisturized at all, according to the American Academy of Dermatology. Even though your tongue does briefly wet them and bring some immediate relief, your lips dry out as the saliva evaporates, and over time, they become chapped, cracked, and painful.

Biting your lip

woman biting her lip

Biting your lip when you're nervous or anxious is incredibly common. The bad news is that if you do it too much, you might make your lip bleed—and when you have a sore, you're putting yourself at risk of infection, according to Pyramid Family Dental in Sparks, Nevada. Infection aside, lip biting can also lead to pain, discomfort, and swelling.

Biting the inside of your cheek

young white man with glasses biting cheek

If you regularly bite the inside of your cheek, that can result in ulcerations, sores, and infections within the oral tissue—all things that can make it hurt to talk, eat, and do other normal daily activities, according to the TLC Foundation for Body-Focused Repetitive Behaviors. Biting the same area over and over again can also cause white patches called keratosis to develop inside your mouth.

Sucking your thumb

cute baby sucking thumb

For some, this common early childhood habit can be hard to grow out of. If you find yourself continuing to suck your thumb as an adult, you risk a number of negative effects on your physical health. Those can include skin damage and cracking, impaired bite conditions, and problems with speech articulation, according to Paul.

Tehrene Firman
Tehrene Firman is a freelance health and wellness writer. Read more
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