I had a relatively good diet, a regular fitness routine, slept well, visited my doctor, and still ended up unable to walk for 6 months with back pain. That was with access to private medical insurance, in Europe. Even with theoretically unlimited money behind my problem, I was unable to get it sorted quickly. 18 months on and I'm not in bad shape, but I still can't walk for more than a few hours, and have trouble sleeping sometimes.