My husband (Male 21) is obscenely tired. He literally slept 20 hours straight today, got up for 4 hours to eat and shower and went back to bed again for another 8 hours sleep. The thing that concerns me is he is still always tired, despite getting an abnormal amount of sleep on weekends he is still somehow sleepy again after sleeping entire days. He works a regular 7-8 hours a day, gets 6-8 hours sleep on a weeknight, is maybe 10kg overweight and eats healthily, drinks a few coffees during the day, 2 beers a week and non smoking. It seems like he is literally never well rested and it impacts both our quality of life. Does anyone know what this might be or how we could fix this? He won't see a doctor either and Google doesn't have anything helpful besides.
It's a condition that stops the sufferer breathing for a few seconds, hundreds of times a night. This leads to exhaustion of the sort you describe.
He must go to his GP and describe is symptoms, the GP may refer him for an overnight sleep study which will establish if apnoea is present, and advise treatment.
This should not go un-diagnosed, your husband needs to address this, his long term health could be affected if he continues to ignore it.
If he won't see a doctor, then there is little point in posting and asking for suggestions as all answers will involve a medical consultation.
Sleep apnoea ....a possibility although you haven't mentioned snoring in your post and he is a bit young for a thyroid problem.....but still ap possibility.