Medical Grounds

[karenf]

My gt grandfather went to join up but he was not allowed on medical grounds (apparently he had a heart defect) Does anyone know if there are records for this? His 4 brothers all joined the services, so obviously they did not suffer from the same defect. One brother died(my daughter laid a poppy at his plaque, 2 yrs ago on a WW1 school field trip, at Tyne Cot), another brother appears to have been a bit of a rogue, judging by his service records (nothing major, one charge was being a nuisance with a fire bucket)
Did men who were turned down on medical grounds have to carry documents attesting to that?
Thank you for any help
karenf