Talk to General Physician on Weakness, Stop Eating, Unable To Walk

My grandfather 70 plus hai. Unhy with the passage of time kafi ziada weakness ho gai hai. Ab wo khud se chal b nai sakty. Kabi kabi pehchanty b nai hai. Kabi khud khana kha laty or kabi bilkul nai. Ham kafi doctors ko check karaea but koi farq nai para. Need senior doctors suggestions please what we need to do.