When my fiance lays down at night he says he feels his pulse throughout his body. Also when he gets real stressed. I know it's normal to sometimes feel your pulse in your neck, but he says it really freaks him out. We went to a doctor and had an EKG done. They said he was very healthy. Could this just be a mental problem or could maybe something actually be going on with his heart or something?

I would take great comfort in normal heart sounds and EKG testing.
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My dad had a sudden heart attack that completely stopped his heart... fortunately it was on a construction site where a nurse was on duty to bring him back. Later he told me that when his heart stopped he realized that he had always felt it beating but was not aware of it. Thereafter he said he was always aware of it when he was resting; he found it comforting!

my son had the same problem ,he said he felt like his heart was beating so hard that he could see his shirt jumping. he wore a holter monitor and they finally saw it and put him on meds. he was dx with svt shot for superventriculartackycardia........svt