Published: 2022-05-10 18:38:37 BdST
Thorpe, who played 100 Tests for England between 1993-2005, had taken up coaching since retirement and was named head coach of the Afghanistan senior men's team in March.
"Graham Thorpe has recently fallen seriously ill and is currently in hospital receiving treatment," the PCA said in a statement on the behalf of Thorpe's family.
"His prognosis is unclear at this stage and we ask for privacy for him and his family at this time."
He was previously England's batting coach but stepped down in February following their 4-0 Ashes defeat by Australia.