America’s Top 8 Nervous Habits

How to curb our destructive behaviors and calm the emotional triggers.
© MSN Healthy Living // © MSN Health
Most actions we perform are intentional and deliberate. But stressful circumstances have a strange way of altering our mindfulness and focus. When we’re tense or anxious, habitual behavior takes over. When that freshly opened bag of cookies is suddenly half empty—and we don’t remember eating them—we’ve resorted to unconscious behavior to placate our emotional turmoil.
Nervous habits, such as nail-biting, are unappealing to watch. Even worse, they can exact a toll on the body. Check out our list to learn how the damage gets done.
Hair twirling and pulling
Habit:
Twirling one’s hair can be a flirtatious gesture in social situations. But for people who twist their locks on a regular basis, the activity can bring health consequences. Obsessive hair twirling can be a nervous-system modulator, says Dr. Melissa Piliang, a dermatologist at Cleveland Clinic. In other words, she says, the activity can be soothing to someone who’s stressed or nervous (discover more self-soothing techniques) and stimulating to someone who’s bored.
Because constant hair twirling or pulling might suggest an unprofessional demeanor, many people who can’t control their hair-tugging habit have learned to do it privately, in their offices with the door closed.
Typically, Piliang says, twisters tug at a handful of hair. Other, highly nervous individuals may feel impelled to pluck the hair out of their scalp, usually one strand at a time. This can be an inherited condition known as this, which makes the pullers feel emotionally soothed. (These people, who often possess perfectionist tendencies, may also derive satisfaction from pulling out certain facial hair.)
Damage: Hair-pulling may result in patchy areas of baldness and, over time, the hair follicles can become damaged, Piliang says. Because this obsessive activity is often rooted in shame and guilt, cognitive or behavioral therapy (see which kind) is one of the best ways to stop it, she says.
1 of 9 Woman on bed playing with hair (© Maria Teijeiro/Cultura/Getty Images)
Habit: If you continue to smoke because you think it calms you down, think again. Nicotine, the addictive substance in cigarettes, only makes it seem that way.
“The drug nicotine is actually a stimulant (see another common stimulant) that makes you more nervous,” says Benjamin Toll, a clinical psychologist at Yale School of Medicine, where he’s also an assistant professor of psychiatry. What nicotine does is bind to certain sites in your brain, which increases the level of dopamine, a neurotransmitter and feel-good hormone. In other words, Toll says, you need to continue to smoke at fixed intervals to keep enough addictive nicotine in your system to ensure you’ve got plenty of dopamine, which research has associated with pleasure.
Nicotine has another trick up its sleeve, Toll explains. The only way to keep nicotine levels up is to take smoke breaks, which are often welcome relaxing escapes from stressful situations. “Over time, the smoker begins to associate these moments of calm—the cigarette breaks—with the smoking itself,” he says.
Damage:  A massive amount of research associates smoking with lung cancer, respiratory illness and a host of other health issues. (What other health risks come with smoking?) Toll says recent research shows that using these nicotine products, combined with counseling, can be effective. “It’s very important that people get counseling while using the patch and lozenges,” he says. “Smoking is an addiction, and you need to address this habit in the same way you’d address taking drugs.”
2 of 9 Woman lighting up cigarette (© Felipe Rodriguez Fernandez/Getty Images)
Habit: Strong enough to masticate sinewy and fibrous foods, our teeth are often unable to withstand the force of grinding. Teeth grinding, also known by this name, is typically the uncontrolled movement of teeth front to back and side to side, says Dr. C.R. Hoopingarner, a dentist and an adjunct associate professor in the department of restorative dentistry at the University of Texas Health Science Center in Houston.
Damage: Grinding our teeth when we’re asleep (learn about the stages of sleep), happens typically when we switch from deeper to lighter levels of sleep. During this switchover, everyone’s teeth tend to grind.
Ideally, nocturnal bruxism lasts only a few seconds. But some people manage to move top and bottom teeth together—literally wearing them down over time—for as long as 30 minutes at a stretch, Hoopingarner says, adding that many studies have linked the activity to stress. (Tips to relieve stress.) Nocturnal bruxism is especially harmful to the teeth, because our sleep state causes us to lose certain protective reflexes that can stop us from doing excessive damage. A protective nighttime appliance can keep the teeth from wearing down, he says (see ways to prevent grinding).
During the day, instead of grinding, people may clench their teeth in a static position. Clenching may cause problems, Hoopingarner says, such as the loosening of the periodontal ligament that holds the teeth in the bone, or of the teeth themselves.
Clenching can also stress and fatigue the muscles, including the masseter, temporalis and internal pterygoid, all three of which are associated with closing the mouth. Massaging the area may help relieve the tightness (ways to massage the jaw). Hoopingarner also suggests behavior modification techniques, such as self-checking for clenching after a frequently performed daily task. In the daytime, he says, upper and lower teeth should always be slightly apart.
3 of 9 Man clenching his teeth (© bilderlounge/Getty Images)
Habit: For many people, a well-manicured hand is a point of pride. However, some can’t leave their nails alone because they perceive imperfections, Piliang says. This habit of “improving” the nails—by biting either the nail or pulling at the cuticle to “fix” the problem—often begins in childhood. Not surprisingly, she says, the more ragged your nails look, the more you’re tempted to bite them (find tips for a great manicure). 
Damage: When people chomp their nails down to nail bed, the skin can become raw and inflamed, Piliang says. Because the nail and the cuticle overlap to keep water, bacteria and fungus out of the nail, any injury to this area can create mayhem, she says. One possibility is paronychia (learn what this is). 
Over time, nail-biting can weaken and damage the nails, she says. Many nail-biters find it difficult to stop the habit, even though they’ve been confronted by friends and family members (discover nail-biting remedies). Piliang suggests keeping the hands very clean and covering them, when possible. Over-the-counter products, which involve coating the nails with an unpleasant-tasting substance, are also worth trying, she says (find some products).
4 of 9 Man biting nails (© James Darell/Getty Images)
Habit: When stressed or anxious, some people obsessively cross and uncross their legs and swing their feet (find ways to relieve stress). These relatively brisk movements seldom cause problems. The potential for health damage comes from how you sit with legs crossed, says Yogi Matharu, a physical therapist at University of Southern California University Hospital, and assistant professor of clinical physical therapy at USC.
When you sit with your legs crossed, the body’s weight tends to shift to one side of the buttocks, instead of being evenly distributed across the sitting bones, Matharu explains. The pelvis rolls backward, the upper back goes from a straight to a rounded position, and one or both shoulders tend to slope forward and downward. The neck now needs to extend to allow the head to look straight ahead. People often feel very relaxed in this slouchy position, he says, and they’re unaware that the way they’re sitting may affect their health.
Damage: In the short term, sitting this way can cause compression in the sciatic nerve, which runs from the spine, through the buttocks and down the legs. This squeezing of the nerve may decrease blood flow, and lead to pain (see other symptoms), numbness or tingling in the legs. It may also result in nerve irritation, a condition that he says might require weeks of recovery.
More serious long-term consequences may include neck or low back pain, headaches and other chronic musculoskeletal problems.
For acute conditions, Matharu helps patients find their most appropriate seated position to keep their spines in alignment (what is the proper sitting posture?). He also suggests they periodically check and correct their body position during the day. When the condition has become chronic, Matharu suggests treatments that include exercise, stretches, manual therapy and using other equipment or aids, such an ergonomic keyboard (learn more about ergonomics). “To fully address these issues, patients must focus on the root of the problem, which is correcting the seated posture,” he says.
5 of 9 Man with legs crossed (© Reza Estakhrian/Getty Images)
Habit: What’s that sound? It’s someone’s knuckles getting a deliberate workout. The ear hears what seems to be cracking. But there’s no real cracking involved. The sound is associated with the release of gases, says Dr. Steven Beldner, an orthopedic surgeon in New York City with a specialty in treating hand, wrist and elbow disorders. Many knuckle-crackers say the activity relieves stress and feels as good as taking a nice short stretch (find other ways to relieve stress).
Here’s what happens: The joint capsule—it’s the covering of the knuckle joint—contains synovial fluid, which keeps the joint lubricated and nourished.  This fluid also contains dissolved gases, including oxygen, nitrogen and carbon dioxide.
Pressing the knuckle in a certain way reduces the pressure inside the joint capsule (learn more about the joints in the human body), says Beldner, who’s also an assistant professor of orthopedic surgery at Albert Einstein College of Medicine. This creates the popping sound associated with the sudden escape of the dissolved gases. He likens the action to a cork popping out of a champagne bottle.
Damage: Despite the foreboding sound, the damage that comes from knuckle-cracking is generally the irritation it causes friends and family, Beldner says. Habitual knuckle-crackers do it as many as 200 times a day, waiting long enough in between cracks for the gases to redistribute, he says. Research has shown the activity does not significantly increase the risk for this condition over time.
Some children’s avid knuckle-cracking alarms their parents. The good news is that kids tend to grow out of it. For adults whose marriage or jobs are at stake because of their habit, which they’re unable to control on their own, Beldner suggests they see a behavior-modification therapist.
6 of 9 Man cracking knuckles (© Image Source/Getty Images)
Habit: Do you know where that pen you’re chewing on has been? You’d better. The mouth is one of the main conduits of germs entering the body, says Philip M. Tierno Jr., director of clinical microbiology and immunology at New York University’s Langone Medical Center and the author of The Secret Life of Germs. And, he says, it’s a nervous habit that somehow causes pens, pencils and other items—all laden with germs—to find their way into our mouths.
Damage: Tierno puts the number of germ types at about 60,000, with only 1 percent to 2 percent being pathogens capable of doing serious physical harm to humans. If these overt, more potent pathogens land on your pen—perhaps through being contaminated by work colleagues or family members who’ve touched microbe-laden keyboards, door knobs or phones—you’re out of luck. The result may be this common illness or an acute case of gastroenteritis (what is that?). And, he adds, some microbes can live on objects for days.
His suggestion is to wash your hands frequently (find proper hand-washing techniques), so you’re not transmitting pathogens from contaminated objects you’ve touched—doorknobs, keyboards or desk surfaces—to pens belonging to you or other people. If your oral fixation makes it impossible to give up pen sucking, try substituting another activity, such as drinking cups of tea (find other ways to stop the habit).
7 of 9 Woman with pen in mouth (© Stockbyte/Getty Images)
Habit: Unless you’re washing your face, it’s best to adopt a “hands off” policy for hygienic reasons. But some individuals, especially teenage girls who display anxious or nervous behavior, can’t help themselves, Piliang says (find ways to deal with anxiety).
People whose hands inevitably stray to their faces often experience tingly sensations in the face, which strongly draws them to touch it. Others may actually feel an itch, which is a nervous sensation. Some teenagers even sleep with their hands on their faces.
Damage: These activities may result in blocked pores and acne (find treatments for acne), Piliang says. However, she adds, women who have acne—red bumps or pustules—will often pick at and scratch their blemishes, causing bleeding. Picking at lesions and drawing blood—a condition known by this name or picker’s acne—may result in scarring, she says, and germ-laden fingers also can cause infections.
Although dermatologists can spot this problem immediately, Piliang says it’s generally tough getting these young women to see a therapist because they don’t see scratching their face as a real problem. She suggests that people who can’t stop this habit trim their nails very short (find proper ways to trim your nails) so scratching will not lead to bleeding. She also advises getting rid of these types of mirrors that only fuel the urge to pick.
8 of 9 Woman rubbing face (© Garry Wade/Getty Images)