Personal hygiene habits such as washing your hands and brushing and flossing your teeth will help keep bacteria, viruses, and illnesses at bay. And there are mental as well as physical benefits. “Practicing good body hygiene helps you feel good about yourself, which is important for your mental health,” notes Donald Novey, MD, an integrative medicine physician with the Advocate Medical Group in Park Ridge, Ill. People who have poor hygiene — disheveled hair and clothes, body odor, bad breath, missing teeth, and the like — often are seen as unhealthy and may face discrimination.