A: Dear Jenn

Hands up who's had bad breath? We all have, at times. And over 90% of bad breath is caused by dental hygiene problems - not keeping our teeth clean.

You need four things:

- A good brush (with a tongue brush surface)

- Floss

- Mouthwash

- Sugar free chewing gum.

Give yourself two weeks and really look after your pearly whites. These four make nearly all mouths gorgeous.

Our two tonsils sit at the back of our mouth, one on either side of our throat. To see them we need a good mirror, good light and good stretch of the mouth. Tonsil stones are white cheesy lumps that sit in pits in our tonsils.

Truth is, they don't often affect people your age, Jenn. But they are more likely if we get lots of throat infections, or allergies. Or if our nose is bunged up all the time. They can smell bad, but they are harmless.

In time, tonsil stones drop off and get swallowed with our food. Some of us can wash ours off by gargling. Resist picking at them. You'll gag and might scratch your throat.

I wish I could see your mouth. I bet I could reassure you about your breath. And tell if you're right about the stones. As I can't, please ask your parents to check. Or your GP, or your dentist.

No need to be embarrassed – doctors get asked to sniff and check body smells all the time. Get it sorted. Much better than being unsure or self-conscious for a second longer.

Deep (fresh) breath.