Teeth sensititve to hot and cold ?

Why are my teeth so sensitive to hot and cold ? Is that normal? I once heard it was caused by brushing too hard?

Thanks :)

Buy sensodyne toothpaste which helps with the sensitivity. A fluoride from the dentist helps too. Cold sensitve is one thing but the hot maybe another story. Hot is more of a serious situation...go to your dentist if you have to for his opinion..good luck!

The dentine of the your teeth may have got worn out, use a senstive toothpaste . From http://dentalspecial.org/
I don't know why this is but switching to Crest Sensitivity toothpaste helped me a lot. It helps build up your enamel against hot and cold food/drinks.

However, if the problem still persists then you'll need to ask your dentist about it.
I have that problem to. i switched to a prescribed toothpaste from my dentist. it is 14 dollars a tube, but well worth it! ask you dentist about prescribed toothpaste.