Father-of-four Geraghty retired from inter-county football in 2012 but had continued to play for his club into his mid-40s. Last November, several of his winning medals were taken during a robbery on his home although some of them were later retrieved.
There has been an outpouring of well wishes for the Seneschalstown and Clann na nGael man on social media.
Kieran Donaghy posted on Twitter: “Graham Geraghty was my first roommate with the international rules. Looked out for me during that time and what an absolute baller. Get well soon to one of the best Royals we have ever seen.”
Tomás Ó Sé tweeted: “Prayers with Graham Geraghty and his family. Hopefully he will be ok. Great fella”.
Former Mayo footballer Conor Mortimer wrote: “Prayers to Graham G, Amanda and all his family this morning upon hearing of the news. Was only chatting to him a few weeks back. will be fighting strong no doubt and please god recovers well. A true giant of our game."