Shift work sucks. By the time you get your body normalized for day shift, here comes night shift. I worked 12 hour rotation for nearly 15 years. I was always lacking energy. Now I have an anemia and lack energy which feels a lot like the drag I had when working. They say shift work takes 7-15 years off one's life. I guess I don't have a lot longer, but the chemical exposure is likely worse than the shift work. I'm SURE it's what gave me the blood cancer I have.