I need some answers im desperate. My dad has been sick for about 4 months. it started out in about november when he was sleeping all the times on the weekend but could still go to work through the week. he works second ****. Finally right before thanksgiving he decided to go to the doctor because he was sleeping all the time they tested him and said he had mono. He still was going to work but was slowly still getting worse. In december he was off for christmas shut down and hasnt been able to go back since. He tests negative for mono now but nobody can figure out whats wrong with him he sleeps all the time maybe is awake 3 hours a day,hes weak,light headed,his left side has a dawl pain,short of breath, only eats alittle. All of his blood work comes back fine he has had chest x-rays cts of his belly and an altra sound of his left side and it all comes back fine. Can you think of anything that may be causing a healthy active man to be so sick he cant do anything?