What is nausea?
Nausea is the sensation that the stomach wants to empty itself, i.e., feeling as one is just going to vomit, while vomiting (emesis) or throwing up, is the act of forcible emptying of the stomach.
Vomiting is emptying the stomach as a result of strong gagging and retching that leads to throwing up. The stomach’s contents are forcefully expelled through the mouth. Vomiting can come in waves as the natural movement (muscle contractions of the digestive system known as peristalses) is reversed, and involuntary contractions in the walls of the stomach and esophagus force the stomach contents out. Sometimes coughing or spitting up mucus from the lungs is confused with vomiting. Vomiting can only come from the stomach.
Retching is the reverse movement (peristalsis) of the stomach and esophagus without vomiting. Sometimes this is called the dry heaves. Continue reading