Same thing happened with my mom & my grandpa a couple years ago. He's 87 now (turns 88 this October) and lives in his house with his youngest brother (who's pushing 70). They're like the odd couple & pretty much keep to themselves because grandpa doesn't want his kid brother telling him what to do (yes, gramps is a stubborn old coot!)
Anyway, a couple years ago grandpa wasn't eating right. Wasn't drinking enough water and didn't open his windows in the summer (doesn't have air conditioning either). He became extremely dehydrated & lethargic (obviously) and mom ended up calling the ambulance to take him to the doctore after he couldn't get up out of bed when she came by to check on him. He was in the hospital for almost a week and then was transferred to a nursing facility for a couple more weeks in order to get some PT. After this episode, he signed power of attorney over to mom. It took him being in the hospital to do this...he's always been a very strong, independant (stubborn) man.
Since then, he's been much better. Mom checks in on him practically every day (at least every other day) and brings him food & makes sure he takes his medications. Other than being in the early stages of Alzheimers, he's pretty darn healthy.
There will be a time soon though that he's going to have to get into a LTC facility. It's very hard on mom to make sure he eats & drinks & takes his meds, but he does listen to her (shock), so it's working out at the moment.
I totally feel for you and your mom. It's a really tough thing to go through. My grandpa is very stubborn & it sounds like yours is too. He may not have anything wrong with him, like cancer or what have you...like my grandpa, he may just not be hungry because of his age or he may forget to eat. That was the case with mine.
It's a tough situation. I hope everything works out okay soon for you all.
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