I had pains in my chest once and was convinced I was having a heart attack of some sort.
Went to the hospital and they couldn’t find a thing wrong with me. ECG fine, no heart attack hormones in my blood, blood pressure was alright... but these pains in my chest were like someone was standing on my chest.
They had a guess and put it down to stress/anxiety but never actually diagnosed anything.
It went away after a few days, never came back.