I woke up choked last night. what this could be? the experience was very bad.

Some causes: Waking up, choking, and gasping for air is typical of sleep apnea.Sleep apnea is when breathing stops temporarily, for up to a minute at a time, during sleep. Sleep study monitor breathing, heart rate, oxygen level, eye movement and brain waves while sleep in a sleep lab. Reflux can come all the way up into the mouth and nose from stomach and cause choking from aspiration. Diagnostic studies.