Severe nausea with no vomiting diarrhea or any other symptoms for over 12 hours. what could it be?

Nausea: The nausea is nonspecific at this time since no other symptoms have developed. Possibilities include early viral gastroenteritis, irritation or inflammation of the stomach lining, reaction or indigestion related to a recent food or drink or medication, pregnancy,etc. Drink some room temperature flat ginger ale and eat lightly(saltines, broth) but see your physician if abdominal pain, vomiting occu