What this feeling usually is

Grinding or clenching teeth during sleep, known as bruxism, is common and often goes completely unnoticed by the person doing it. It's usually discovered through a sore jaw in the morning, headaches, or a dentist pointing out tooth wear, rather than the person feeling it happen.

Common lifestyle causes

What's happening in the body

Bruxism is thought to be connected to the same stress response that creates muscle tension elsewhere in the body, except it plays out in the jaw specifically, and during sleep when there's no conscious control to stop it. Because it happens during sleep, especially lighter sleep stages, the person grinding has no awareness of it happening, which is why it's usually the after-effects (jaw soreness, headaches, tooth wear) that reveal the pattern rather than the sensation itself.

General suggestions that may help

When to consider seeing a doctor

Occasional grinding is common and often manageable with stress reduction. See a dentist or doctor if you notice tooth wear, frequent jaw pain or headaches on waking, or if a partner reports loud grinding regularly, since ongoing grinding can cause real dental damage over time.