A Practical 5-Step Approach to Nausea and Vomiting.

Nausea and vomiting (N/V) are common presenting complaints in the outpatient and inpatient settings. These symptoms can be associated with high morbidity and poor quality of life, particularly in those with chronic symptoms. The clinical approach to N/V can be challenging, given the numerous possible underlying causes as well as the vast array of diagnostic and therapeutic options. In this concise review, we provide a practical 5-step approach to the clinical evaluation and treatment of N/V, suitable for application in the primary care and subspecialty settings. The 5-step approach includes (1) defining what the patient means by N/V, (2) determining whether symptoms are acute or chronic, (3) considering medication or toxin adverse effects, (4) using the patient's presentation, severity of symptoms, and physical examination findings to formulate a differential diagnosis and to guide evaluation, and (5) directing treatment on the basis of knowledge of neurotransmitters and receptors involved in the emetic pathways. We discuss the pathophysiology (neuronal pathways and neurotransmitters), differential diagnosis (medication and toxin adverse effects, neurologic causes, gastrointestinal diseases, metabolic and endocrine conditions, and psychogenic disorders), initial evaluation and risk stratification, and management and treatment options. Management of symptoms that are acute in onset or mild in severity may involve an empirical trial of antiemetics without extensive testing. In contrast, when symptoms are chronic or moderate-severe, testing for an underlying cause should be performed, and medication adverse effects, neurologic causes, gastrointestinal diseases, metabolic or endocrine conditions, and psychogenic disorders should be considered in particular.