My father has been suffering from chronic fatigue for a long time; he is now 50, and has been experiencing this since his early 30s.
It isn't chronic fatigue syndrome; he doesn't have joint pain or any of the flu-like symptoms associated with CFS. He simply gets exhausted easily, has strange sleeping habits (sometimes gets tired and goes to bed early, waking up in the early hours of the morning). I don't think we've ever tried to find an exact diagnosis for this problem, instead settling on a genetic disorder (but no one else in the immediate family has the same kind of fatigue). It has gotten slightly worse over the years, but perhaps that can be attributed more to aging than anything.
He says that he's been feeling more tired this year than last, so I thought I would start looking into the matter. He has several benign liver cysts, two of them greater than 3 cm in diameter. However, he recently had a checkup, and he was told that the cysts have exhibited no growth since last year, but perhaps the liver is part of the problem.
He doesn't have a drinking problem, but will have a can of beer or glass of wine every day or two. He just pledged to stop drinking alcohol entirely, in hopes that it will alleviate the fatigue. Furthermore, he tends not to eat very healthily, which is not to say that he has any weight problem (6' 2" and 190 lbs.) because his metabolism is uncharacteristically good at breaking down the things he eats, including mixed nuts and Breyers' butter almond ice cream, which he said he will now consume less of.
Finally, whether it is pertinent or not, he has severe toothaches on his upper-right teeth when he eats more "inflammatory" meats (I'm not really sure what the best for this is in English) but spicy and sweet pork, things like that. About six months ago, after a particularly bad toothache, he briefly lost hearing in his right ear upon waking up one morning. His hearing was restored about 5 days later, without any action taken.
Please suggest diagnoses/treatments that might help, and please ask more questions about the symptoms if you feel that is necessary. Thanks!