I have it.Have had all the tests including brain scan which was clear.Most Docs will just fob you off as there is no cure and not much they can do.You should go for a proper hearing test and examination just in case there is something in the inner ear or, as i have said,a problem in the head causing pressure.
Dont bother to read all the stuff on the internet sites,i've been there and done all that and nobody really knows what causes it.Though best guess is always been 'occupational' noise.I did a big and very noisy job a few months before mine started about 18 months ago,stupid enough not to use ear protectors,and i recon thats what caused mine.
Dont notice it much ,if at all,during the day when i'm working and there is background noise,worse time is at night and when trying to get to sleep.
Advise is to listen to 'White noise' (inter station noise) you can buy tapes.
At night i plug myself into the Ipod and listen and it calms things down and gets me off to sleep.
It is worse for people who are loosing their hearing as well so get that checked.