Dandruff -- those dry, white flakes of skin you brush off your collar or shoulders -- is harmless. But it can be embarrassing and itchy. Dandruff really isn't about your hair, or how often you wash it. Instead, it's about the skin on your scalp.
Skin cells that grow and die off too fast are the problem. Exactly why that happens isn't clear. A very common fungus called malassezia may contribute to dandruff. This fungus lives on the scalp of most healthy adults without causing any problems. One theory is that the immune system of someone with dandruff may overreact to that fungus.
For Crystal Barry, excessive sweating wasn't just a nuisance. It shaped her daily activities, even her personality.
Barry, 24, a student from St. Louis, avoided team sports and crowded events. She never wore tank tops or sheer fabrics and often had to bring extra shirts to school after her first shirt was soaked through with sweat. She shied away from social situations, especially ones involving the opposite sex. "I don't like to be around people if I stink," she tells WebMD. "I get real quiet."