always sleepy and tired

as soon as my husband comes home from work, whether it's 8,10 or 12 hours, he eats super and falls asleep. he can fall asleep at 5:00 p.m and sleep untill 10:00p.m stay awake for an hour and go right back to sleep for the rest of the night until 6:00 the next morning.that happens all week. then on weekends he wakes up at 10:00a.m stays awake for about two or three hours and sleeps the rest of the evening. sometimes he wakes up for acouple of hours then right back to sleep he goes. he can be wide awake then look over at him he starts yawning saying he's tired and he's knocked out again.he has fallen asleep when we take a trip somewhere and sleeps almost the entire 6 hours or more. he dont walk into a store or anything and start falling asleep but most of the time he's yawning ready for bed.he is sleeping his life away. if anyone thinks they can help please give me an answer. we dont have insurance so it's hard to go to the doctors to get answers, please try to help. thank you.