When you're lying down, mucus will start pooling in the back of your throat, aka postnasal drip

. Another reason why coughs get worse at night is acid reflux. Don't forget that acid is an irritant to the throat, much like mucus, germs, or dust.

How do I stop coughing at night?

Why do coughs increase at night?

Coughing often becomes worse at night because a person is lying flat in bed. Mucus can pool in the back of the throat and cause coughing. Sleeping with the head elevated can decrease postnasal drip and symptoms of GERD, which both cause coughing at night.