A palliative care clinician explains the ins and outs of nausea and vomiting in people living with serious illness, including causes, treatment, and patient-education.

Clinician talking to a patient that has nausea and has been vomiting to discuss treatment options

In patients grappling with serious illness, the focus often centers on the illness itself, sometimes overshadowing the holistic experience and its impact on the patient's quality of life. While pain and shortness of breath are readily apparent, other symptoms may be subtle or downplayed by patients due to the perception that they are trivial.

As a cancer survivor and a palliative care physician, I've observed firsthand how symptoms like nausea and vomiting can overshadow the illness itself.

Nausea is one of those symptoms. Often dismissed as insignificant, nausea can be debilitating for patients. As a cancer survivor and a palliative care physician, I've observed firsthand how symptoms like nausea and vomiting can overshadow the illness itself, profoundly affecting both patients and caregivers. Nausea and vomiting, which are highly distressing for sufferers, significantly disrupt daily activities. Prevalence rates of nausea range from 6-68% in advanced cancer, 17-48% in heart disease, 30-43% in renal disease, and 43-49% in patients with AIDS. Nausea and vomiting, while distinct, commonly coexist, universally impacting the quality and quantity of life in patients with serious illnesses.

The difference between nausea and vomiting

It's crucial to distinguish between nausea and vomiting, as they can occur independently. Nausea refers to an unpleasant, queasy feeling in the throat or stomach, potentially leading to vomiting. It is primarily a cerebral sensation, and there is limited understanding of its mechanism and neurophysiology. Vomiting, on the other hand, involves the expulsion of stomach contents through the mouth, often accompanied by retching, the reverse movement of the stomach and esophagus.

Causes of nausea and vomiting

Various factors contribute to nausea and vomiting, including bowel obstruction, infections, medications (e.g., chemotherapy), intracranial issues (e.g., raised intracranial pressure), vestibular disorders, dehydration, food poisoning, migraines, pain, constipation, and anxiety. Comprehensive patient assessment is essential for identifying the underlying cause, as many diagnoses can be made without requiring lab tests or imaging.

Triggers: the four emetic pathways

While nausea and vomiting present with common, predictable, and distressing symptoms, their triggers vary across four emetic pathways: the Chemoreceptor Trigger Zone (CTZ), gastrointestinal tract, vestibular tract, and cerebral cortex, transmitting signals to the brain when activated.

How to treat nausea and vomiting

Before discussing the pharmacological and non-pharmacological approaches to treatment, I would like to stress that addressing health care disparities, especially concerning access and quality of care for people of color, is crucial. Historically, access and quality of care for persons of color have been systemic issues in health care. Every clinician is responsible for addressing the needs of all of their patients. This can be accomplished through active listening and equitable diagnostic and treatment approaches.

Treatment for nausea and vomiting should begin with identifying reversible underlying causes, such as surgical intervention for bowel obstruction.

After this, the first and most critical steps are to ask every patient whether they are experiencing nausea—and to believe and prioritize every patient's report of nausea. Treatment for nausea and vomiting should begin with identifying reversible underlying causes, such as surgical intervention for bowel obstruction. If the cause is irreversible and the patient requires symptomatic relief, pharmacological interventions targeting specific neurotransmitters along the emetic pathway should be considered. Patient education on both pharmacologic and non-pharmacologic approaches is also essential.

Considerations when educating patients

Educating patients and caregivers on the causes of nausea and vomiting and reassuring them that this is common, often predictable, and most importantly, treatable is key. Non-pharmacologic strategies like frequent small meals, odor avoidance, and relaxation techniques not only complement pharmacological treatments but also give patients some control over their symptoms.

Targeted treatment for nausea and vomiting

Treatment options may be targeted towards the likely mechanism of nausea—or they may be empiric.

Medications targeting specific emetic pathways include antidopaminergics (e.g., Metoclopramide), 5HT3 antagonists (e.g., Ondansetron), antihistamines, anticholinergics, NK1 antagonists, dexamethasone, cannabinoids, ginger, and lorazepam. Treatment should be tailored based on patient factors, identified causes, and associated emetic pathways. The table below highlights considerations for targeted therapy. An empiric approach may be trialed when the cause of nausea and vomiting is unclear.

Considerations for targeted therapy

Considerations for targeted therapy for nausea and vomiting
Emetic Pathway Common Causes Neurotransmitter Treatment
CTZ Medications
and chemotherapy, infection, electrolyte imbalance
(Haldol, Metoclopramide), 5HT3 antagonists (Ondansetron)
GI Tract Bowel
obstruction, gastroenteritis
(Haldol, Metoclopramide), 5HT3 antagonists (Ondansetron)
sickness, tumors of the inner ear
(promethazine) and
anticholinergics (scopolamine)
medications (Lorazepam)

Empiric treatment for nausea and vomiting

When the cause is multifactorial or unclear, first-line treatments for nausea and vomiting should include antidopaminergics and/or 5HT3 blockers due to their efficacy, particularly in CTZ and gastrointestinal tract involvement. Given that nausea and vomiting often involve the CTZ and gastrointestinal tract pathways, first-line empiric treatments typically involve antidopaminergics and/or 5HT3 blockers. Emerging literature supports the efficacy of 5HT3 blockers, particularly due to their favorable side effect profiles.


Nausea and vomiting pose significant challenges for patients living with serious illness, necessitating comprehensive assessment and tailored interventions. Clinicians equipped with knowledge of emetic pathways can effectively address these distressing symptoms, ultimately enhancing patients' quality of life.

For further resources, consider exploring the CAPC clinical training course on Nausea and Vomiting, a recent case review on nausea and vomiting, and the Palliative Care Network of Wisconsin's Fast Facts.

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Edited by Melissa Baron

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