I had a terrible bike crash while doing a scary fast switchback descent. My bike left the road and hit a huge rock. The bike stopped and I didn't. I went right over the handlebars and hit my head on another rock. It knocked me unconscious and my helmet was cracked in 3 places. The doc at the er said my head would have cracked like a watermelon without the helmet--it saved my life. I suffered a concussion and vertigo for months afterward.

Shooting Star, I know how your friend feels. It's scary laying down in bed when you have vertigo and I was off the bike for several weeks. I went to an ENT who performed a procedure by turning my head several directions to make my brain and inner ear readjust itself. Sounds crazy but it worked. You might want to suggest it to your friend.