I often wake up coughing at night. how do i know if it is due to post nasal drip or silent acid reflux?

Nocturnal cough: Nocturnal coughing may be an asthma reaction without wheezing. Remove dust collectors and pets from bedroom. Use a humidifier if environment is too dry. Post nasal drip would most likely also bother you during daytime. Reflux, if a problem, requires you to avoid eating prior to bedtime and elevating the head of your bed. I assume smoking isn't the problem.