Scott,
Do you have vertigo all the time? I started having vertigo 20 years ago during allergy season but I only got dizzy when my head was in a certain position. The doctor always said it was an inner ear problem caused by fluid imbalance in my ears and prescribed antihistamines which didn't help at all. Two years ago I went to a different doctor who finally figured out that I had positional vertigo that was caused by irregular sized calcium grains in my middle ear. Some of the calcium grains had gotten bigger and didn't roll around around the same as the smaller grains. This confuses your brain and it doesn't know which way is up. The first time it happened I would get instantly dizzy if I looked up and if I didn't grab ahold of something I would fall down. If I was laying on my back and rolled my head to the left the room would start spinning followed by instant nausea. Anyway to make a long story a little shorter he gave me a sheet of paper that showed some procedures that he said should retrain your brain for the changes in the your inner ear grains. Doing these procedures has always cleared up my vertigo in three days. I hope it works for you.
Victor
http://www.dizziness-and-balance.com/disorders/bppv/home/home-pc.html 
