Why is it that i keep clenching my teeth when i'm asleep?

Teeth clenching: There are many reasons for clenching your teeth. (stress, occlusal imbalance) your dentist can do a better evaluation and you should possibly consider having a mouth guard made to protect your teeth while you are clenching.

Nighttime Bruxism: Grinding or clenching of the teeth at nighttime is called nocturnal bruxism is a common sleep disorder called parasomnia. It is related to stress levels generally. Bite devises are typically used to limit the damage to teeth and jaw joint.