Bruxism is a condition that causes the person to grind their teeth, often at night while sleeping. Bruxism can cause your teeth to become weak or worn down and can even cause them to become cracked or broken. If you grind your teeth at night, your teeth can crack or chip, may lose some of their tooth enamel, and your teeth may become more sensitive to hot and cold temperatures. Unfortunately, most people are unaware whether they grind their teeth while sleeping.