You're not alone - nocturnal grinding (known as bruxism) is a common condition. Most people who grind their teeth while sleeping are quite unaware of it, and only find out because their sleeping partners complain of the noise.

You should visit your dentist to find out whether the habit is causing any damage to the enamel of your teeth. Unfortunately, enamel can't grow back so any damage done is permanent, although modern dental treatments can help to repair it.

When you see your dentist it's also important to tell them about any other dental or facial symptoms you may have, especially waking with an aching jaw, or if you have noticed a clicking jaw joint.

In most cases, bruxism doesn't usually cause much damage to the enamel, and it's more a matter of irritation to those you sleep with.

The causes are varied but stress plays a part in most cases. Less frequently there's a problem with the top and bottom teeth coming together (called an occlusal discrepancy). If the grinding has been going on for some time the teeth may be ground down so far that they all fit together very well.

There are two approaches to treatment:

• To break the habit your dentist may fit a plastic night-time dental appliance. You wear this like a gum shield, and it prevents the top and bottom teeth locking together.
• For most people, treatments aimed at reducing stress will help stop the problem. These range from counselling to de-stressing therapies, muscle relaxants and even tranquillisers.

This article was last medically reviewed by Dr Trisha Macnair in August 2008