Because teeth grinding—or Bruxism—often occurs during sleep, most people are unaware that they do it. However, if you often wake up with a dull, constant headache or a sore jaw, there is a good chance you are grinding your teeth at night. Many times, people learn that they grind their teeth from a close family member or bed partner who hears the grinding at night. 

Bruxism is a common sleep disorder that affects 10% of the adult population and up to 15% of children; rates decrease with age. It is thought to be caused by stress.

Grinding one's teeth erodes tooth enamel and can damage dental work. If you suspect you may be grinding your teeth, talk to your dentist. He or she can examine your mouth and jaw for signs of bruxism, such as jaw tenderness and abnormalities in your teeth. Your dentist may suggest wearing a mouth guard at night.