Is there such a thing as too much sleep?

Your husband is suffering from body-oxygen-intake-starvation, and this is proved by his falling asleep, when his oxygen levels get low he falls asleep. The cure is the big E, Exercise, walking, running, and telling him: "I want you to breathe in and out 3 times a day taking great big breaths." Old people get older by adopting a lazy-ways let me relax lifestyle. It's nature's way to take them to heaven on the next bus going that way.

In your profile you state that your husband has dementia, depression and sleep issues, so I would say sleeping too much is quite normal for him and rightfully so.
Someone with any of the dementias will sleep more(my husband who had vascular dementia slept anywhere from 16-20 hours a day the last 2 years of his life)as will someone that is suffering from depression. And then you add in sleep issues and well....you have the perfect storm.
If you're that concerned perhaps it's best to talk to his doctor about what you're witnessing and see what they suggest.

You put this under the Depression category. If you feel your DH is depressed with his dementia diagnosis, and that's partly to blame for his excessive sleeping *in your opinion*, I'd speak to his doctor about the possibility of trying an anti depressant. My mother who suffered from dementia did well with Wellbutrin max dose (eventually).

Sleeping goes with the territory when dementia is at play. What do you feel he 'should' be doing that he isn't? Dementia strips away an elder's ability to do mostly everything, eventually, which is one reason I hate it with every ounce of my being. If your husband is not miserable and aggressive, consider it a blessing that he IS sleeping and relaxed; that's the truth. This disease can rear its ugly head in many disturbing ways. Sleep is a good thing.

Best of luck.

I wish my Mom would have slept. When she was home she always took a nap in the afternoon. Not at my house. Except for getting up at least once a night she did sleep from about 9 to 8. Started falling asleep by 8. Tried keeping her awake but gave up since still still slept to 8.

If this is your husband with Alzheimer's/dementia you are asking about then increased sleeping is a sign of decline as the disease progresses.
It takes a lot of energy to keep the body functioning. the heart still beats, the lungs still breathe, the kidneys still filter waste, the liver does the same and so on. After eating the body is really expending energy digesting the food just consumed.
Not to mention when he is awake the brain is processing what is going on, what are the noises, what you are saying, the visual things from TV, from looking out the window,. That is not counting the questions you ask, the talk, processing the act of showering, dressing, and all the other activities.
So long story short...sleeping a lot is normal.
My Husband went from sleeping a "normal" 8 to 9 hours at night to sleeping 12 hours at night, naps during the day to sleeping 23 hours at the end of his life.
There is a possibility that he would qualify for Hospice and you would get help and supplies and equipment to help make caring for him easier.

AjosephR, welcome to the forum. It is not unusual with Alzheimer's/Dementia, plus some prescription medicine can make someone very sleepy.

Plus sitting too much, or laying on the bed to watch TV, will make someone doze off.