Updated: November 21, 2008

You dont have to pull out the oven mitts yet; our medical expert Roshini Rajapaksa, MD, presents simple solutions for nail biting and more.

Q: Help me stop biting my nails, please. They look terrible.

A: Nail-biting is a tough habit to break, but there is hope. Start by trying a special nail polish made to help chronic biters, such as Barielle No Bite Pro Growth ($15); its bitter flavor will keep you from going back for more. Chew sugarless gum to keep your teeth occupied. And get a manicure: Seeing your nails nicely polished may encourage you to keep them that way. When you do manage to grow your nails out a bit, keep them clipped short so youll have less temptation to nibble.

If stress is at the root of your nail-biting habit, make time for stress reduction—yoga, walking, chatting with friends, whatever helps relax your mind and your fingers. If youre still struggling, a therapist can help identify the causes of stress and work with you to curb the habit.

Q: Im thinking about getting my navel or nose pierced. Is this dangerous—or reversible?

A: Most people wont have any problems. But there are significant risks whenever a needle meets skin: bleeding, nerve damage in and around the piercing site, or an allergic
reaction to the jewelry. (It should be made of silver or gold, though many people can tolerate stainless steel.) Theres also the risk of contracting a serious infection, like hepatitis C.

Any piercing you get should be done in an establishment thats licensed by your state or local government. But do your own due diligence, too: The facility should be sparkling clean. The technician should wash his or her hands, don gloves, and use a sterile needle— not a piercing gun—for the job. (Try to observe some work in progress before you sit down for your own.)

While the spot is healing, wash your hands before touching it. For navel piercings, wear nonbinding clothing to speed healing and keep infections—and the chance of a nasty snag—at bay. If you decide later to stop wearing the jewelry, most holes will close up over time, although there may be a small scar.

Q: I have ugly stretch marks on my tummy, butt, and thighs. How can I make them go away?

A: Almost 90 percent of us have stretch marks—and wed be thrilled to get rid of them. They can be red and purple, white or silver. They appear when skin stretched by rapid growth (during pregnancy, or major weight gain or loss) doesnt snap back to its original state. Despite claims made on late-night infomercials, no cure-all lotion or cream will make them vanish. Your best bet for diminishing them is a procedure that slowly removes layers of the scarred skin tissue, like microdermabrasion or a chemical peel. Be sure you hire a board-certified skin doctor to do it; most dermatologists suggest six treatments, which typically cost $50 to $250 a session, on any spot that needs work. And you may actually need more.

How to prevent further marks? Weight control is the obvious biggie (and that should be a lifetime pursuit). But staying hydrated and getting regular exercise (which improves circulation to your skin) also help skin maintain its elasticity.

As for all the belly rubs marketed to pregnant women for the prevention of stretch marks, so far theres no scientific evidence to back up those claims. But applying lotions containing cocoa or shea butter,
olive oil, and vitamin E can help your skin retain moisture, and they may relieve the itching that often accompanies dry skin and stretch marks.

Medical editor Roshini Rajapaksa, MD, is an assistant professor of medicine at NYU Medical Center.