Why do i throw up when i cough?

Reflex: Coughing increases your intra abdominal pressure, decreases the pressure in the chest when you breath in. Sometimes this induces reflux acid to come up into the esophagus. You may induce a gag reflex like this or from thick mucus. That types of spasms can be a part of a particular illness called pertussis that you could get checked for.