It's kinda similar to when the alarm goes off, then you dream about it.

I have some chest problem and when i lay down many times i wake up with chest pain as if my chest tears. Well

i was sleeping and I dream about
me and a group of students practicing TOUCHLESS KNOCKOUT punching techniques. I was punching(without touching but coming within inches) my partner in the chest several times. Turns out when i woke up i was having that chest pain that i have!!!!!
my chest was tearing. good thing i woke up and i was able to stand up so I avoided having worse pain