Nails can harbor dirt and germs and contribute to the spread of many infections. Keep nails short. Trim nails often. Scrub the underside of nails with soap or water each time you wash your hands. Clean any nail grooming tools before use. Nail grooming tools should be sterilized before use in saloons. Avoid biting or chewing nails. Avoid cutting cuticles as they act as barriers to prevent infection. Never rip or bite a hang nail instead clip it with a clear sterilized nail trimmer a hang nail is small torn piece of skin next to finger nail or toe nail . Infections of the finger nails or toe nails are often characterized by swelling of the skin or thickening of the nail. In some cases these infections may be serious and need to be treated by a doctor.