Bruxism is a condition in which you grind, gnash or clench your teeth. If you have bruxism, you may unconsciously clench your teeth when you’re awake (awake bruxism) or clench or grind them during sleep (sleep bruxism). Mild bruxism may not require treatment. However, in some people, bruxism can be frequent and severe enough to lead to jaw disorders, headaches, damaged teeth and other problems.