Un-diagnosed illnesses are the worst. A former co-worker of mine suffered from violent episodes of illness for years, and various doctors guessed it was ulcers (which he did have, bit they weren't the issue), etc., and they tried treating him for all of those. Finally, a nurse he knew asked if he'd ever had a particular test done, which he hadn't. Turned out it was his gall bladder. They removed it and he's been fine ever since, but he sufferered through several years of misdiagnoses and incorrect treatment.