Suggest Treatment For Dizziness And Vertigo

Question: I'm trying to figure out what has been causing my dizziness & on and off vertigo feelings that I've been suffering from for the past 1,5 years already.

It all started while I was on vacation 1,5 years ago. I developed a slight pain in my left ear, along with a high pitched tinnitus. The pain went away, but the tinnitus stayed. There was no loud noise exposure involved before this. I was lying on a beach when it started.

A few months after that, I started getting fullness (a pressure sensation) in my left ear. This could come on suddenly and then return to normal again. I noticed that the "effect" was most often brought upon when I was first sitting for a period of time and then got up. Along with the fullness feeling, I also noticed that my hearing in left ear went up and down and I could hear the tinnitus change along with my heartbeat while standing up from a sitting position.

Few months from that, I went on a business trip and needed to fly. I had big difficulties with getting my left ear "open" while the plane was descending. If fact, my left ear stayed locked the whole time and when I finally got of the plane, that's when I had the most horrible vertigo I've got to date. I couldn't walk straight and when I turned my head from side to side, I heard a "whooshing" sound in my left ear. It sounded exactly like there was some fluid in the ear, going from side to side while I turned my head.

I went to sleep and thought it will go away the next morning.

Well, for the most part (the vertigo) did go away, but I had balance troubles the whole next day. I felt like the floor under my feet was soft, felt slightly drunk and so forth.

I've had that slight drunk feeling on ever since. For some reason, in the daytime, I often feel much better and have almost no dizziness at all, but in the morning and especially during the evenings, I get dizzy almost every day.

In the beginning, the fullness feeling was only in my left ear. Today, it's also in my right ear. It seems to be triggered by sitting for a period of time and then standing up, but it also happens if I bend over or strain myself in some way. Also, when I stand up, I often get a vertigo lasting for 20-60 seconds before it goes away. Sometimes this causes me nausea as well.

What I'd like to know is: What tests should I go through next and how do I know if my symptoms are caused by some problems in my ear(s) or if these are caused by some brain related issue.

Thanks!