A couple of years ago, I had to stop riding my two "upright" / traditional bikes due to significant pain in my right thumb and left wrist. Whenever there was constant pressure on either one for more than about 5 minutes, it would flare up.
I was fine on my recumbent and my Electra commuter, where the upright riding position and swept back handlebars keep most of the pressure off.
About a month ago, I decided to take my Fuji Absolute 1.0, which is a fairly high level fitness hybrid, out for a spin. I hadn't notice much pain in my wrist for a while, so I wondered if I might be able to ride for a while. Didn't go far, about 8 miles, but I was fine.
Over the past month I've had it out 3 more times. Just on 15-20 mile rides. I take 2 ibuprofen before riding, as that helps keep down the swelling and pain in my thumb. The rides all went well. It was really fun to be back on this bike, as it is my lightest, fastest bike. And it has such a smooth ride. I do have extra cushy, ergonomic grips and bar ends on, which help.
I thought I might never ride it much again, but now I plan to keep it in my rotation.