Nausea and vomiting are extremely common symptoms and may be caused by a vast array of medical conditions.[1]Koch KL. Nausea and vomiting. In: Wolfe MM, Davis GL, Farraye FA, et al, eds. Therapy of digestive disorders, 2nd ed. Philadelphia, PA: Saunders; 2006:1003-117.[2]Koch KL. Diagnosis and treatment of neuromuscular disorders of the stomach. Curr Gastroenterol Rep. 2003 Aug;5(4):323-30.
http://www.ncbi.nlm.nih.gov/pubmed/12864963?tool=bestpractice.com
[3]Stern RM, Koch KL, Andrews P. Nausea: mechanisms and management. New York, NY: Oxford University Press; 2011. The presentation can be acute or chronic and ranges from a mildly annoying symptom to a condition that impairs quality of life or is a marker of a life-threatening disease.
There are 2 general mechanisms of nausea and vomiting:
Neurologic
Stimulation of the area postrema, which "senses" noxious chemical agents (e.g., poisons, chemotherapy agents, digoxin) and subsequently stimulates the vagal nuclei, which evokes nausea and coordinates the emesis reflex.
Diseases of the central nervous system (CNS) such as infections or brain tumors stimulate CNS structures and elicit nausea and vomiting, ultimately through vagal pathways.
Peripheral
Diseases and disorders that originate in peripheral organ systems, such as the gastrointestinal tract, stimulate vagal or spinal afferent nerves that connect with the vagal sensory (tractus solitarius) and vagal efferent motor nuclei. Ultimately, cortical centers where nausea is perceived and the efferent pathways that mediate vomiting are stimulated.
Tumors, infections, and drugs in the periphery may cause local dysfunction in a variety of organ systems that is sensed as nausea that, when severe, evokes vomiting.