At night while sleeping, i wake up with a racing heart&tons of drainage down throat.i cough after.the fluid&racing heart go handinhand, for months now?

Postnasal drip: Postnasal dripping of mucus while you are recumbent in bed may be caused by excessive dryness or dust collection in your bedroom. I believe that the rapid heart beat is secondary to the nasal dripping and not due to cardiac pathology. Taking an antihistamine like benadryl (diphenhydramine) at bedtime may prevent symptoms but avoid decongestants like Sudafed or neosynephrine nasal spray which accelerate the heart