dizzy teen

[April2]

I wasn't sure where to post this but what could cause a pretty normal, healthy 19 year old boy to get dizzy when he stands suddenly after sitting awhile? He's mentioned this to me several times. He's of normal weight and pretty healthy overall. The only other undiagnosed things he's got going on are ringing in his ears and mild facial tics from time to time. We've had all that tested extensively. They don't think he has Turettes just a facial tic and they can't figure out why he has ringing in his ears. He's had that for about 7 years now. He's had a Cat Scan done and other tests. I still can't figure that one out and whether we should still keep pursuing this.
But now he says he gets dizzy when he stands suddenly after sitting awhile. Is this enough to warrent a trip to the doctor? What could it possibly be? Being a normal teen, I wonder sometimes if he's getting enough sleep. He does go to college and works part time. He's a good kid and I know for a fact that he does not and has not ever done drugs. He doesn't drink. He lives at home and I try and make pretty healthy meals for the most part. Any suggestions as to what could be going on? And is it worth making a doctor's appointment? Also, should I keep pursuing the other things going on? He even saw a specialist about the facial tics so I'm not sure I can go much further with that. I just wish I knew what was going on so I could help him. Does anyone have any suggestions as to what could be going on? Thanks!

[April2]

Thank you for your responding. He did see an ENT specialist years ago but maybe it's time to see one again since it's been awhile. Thank you.

[Dragonladylea]

With the ringing in the ears and the dizzyness I would almost think a trip to an Ears, Nose and Throat specialist. He might have a fluid problem in his ears which would cause the ringing and the dizzyness.