HCM is a thickening of the heart muscles - and it can be fatal - sometimes with no warning. I did not know I had it until an ECG before my hernia op. in 2019 which threw up a red flag. He said he would ring me in two years time as a follow-up. This may be what the footballer who collapsed in the Euros had - not something you want to happen when you are asleep. It's hereditary - both sons have been checked and are ok.
