Stephanie,

It's definitely not just in your head!!!!

I have the same thing. Heat + exercise is a big trigger. Found that out after moving from a moderate climate to a tropical one. I also stopped running for 6 or 7 years after I was diagnosed because I completely passed out a few times. Scary.

I've weaned myself off the medication (but will take it again if I need to) because I can feel it coming on early and do something about it. I too drink a lot of water the night before, the morning of and after a run. I do not drink much, if any, alcohol the night before I run.

You might want to buy a heart rate monitor and look at the low heart rate thread in the basic training forum. Do the C25K. I know you used to be competitive, but it's a good way of easing your body back into things. It's double important for us to start out slow until we get acclimated to heat and running. I've been back running for four or five months. I'm still behind in distance and speed from what I was running seven years ago. But that's fine.

Once, when I started the C25K, I had it in the middle of the run, and I had to sit down. I sat for a while, let my pulse get back to normal, and then went on with my run a lot more slowly.

Now, I sometimes have dizziness at the end or after a run. I just find a park bench and sit until my pulse slows and I feel I can walk home without dizziness. If I get up, and I'm feeling dizzy, I sit back down and wait. If no bench, drop to your heels or sit on some grass until the feeling passes.

You can do this. Start s-l-o-w-l-y, listen to your body, modify, and have fun.

if you don't get a 2nd opinion you're crazy.