I have read some of people's symtpoh's... but haven't read any cures.. I have been suffering with this for 3 yrs now.. it mostly happens when I lay down at night to sleep.. I can hear and feel the heartbeat plausing?/

What causes this? and how to I get rid of it... somenights I can not sleep, cuz the plausing is so strong.. I toss and turn for hours before I can sleep. %-)
Please help..!!
Thank you