Sure, biting and picking at your nails is kinda gross. It also is a sure-fire way to make your manicure that was supposed to last all week last only a day. And while it's a nervous habit that's certainly on the more innocuous side of the spectrum, it can still affect your health.
For starters, biting your nails can raise the risk of catching a cold or other illness because you're putting your unwashed hands in your mouth. It can also raise the risk of paronychia, or infection of the skin surrounding the nail, says Rochelle Torgerson, M.D., Ph.D., a dermatologist at the Mayo Clinic.