Excessive Drooling at Night Could Signal a Serious Health Issue. Drooling while you sleep may seem harmless, but it could be your body’s early warning sign of deeper health issues. First warning: sleep apnea. Obstructed breathing weakens muscle control, causing saliva to leak while you rest. Second: acid reflux or GERD. Stomach acid irritates your esophagus, triggering excess saliva at night. Third: allergies or sinus infections. Blocked nasal passages force mouth breathing, increasing nighttime