It's crazy how much your physical health is tied to mental happiness/lack of stress. I had a friend that during his most stressful period as a 24 year old in Investment Banking had strep throat 4 times in 2 months.
Several doctor visits concluded that it was the long hours and insane amount of stress that was severely crushing his immune system.
Moral of the story is love what you do and take care of yourself: nothing is as important as your own health and happiness
replies(3):