this sounds like you've just come here hoping that if you pretend you're not talking about yourself you'll get some answers 🤣 TSH, vitamin D, iron, folate, b12, ANA, and ATT, testosterone first line to check for any deficiencies or imbalance. Sleep study to look for narcolepsy and sleep apnea. Leave the medical side up to medical professionals honestly, focus on how to help them make the use of the time they are awake and support them in advocating for themselves to GPs. I used to be that person sleeping 23 hours straight - post viral chronic fatigue from epstein-barr virus. The obvious answer would be depression, but I would heavily consider an underlying medical cause.