Assessment and Management of Nausea

Medication‑ and Toxin‑Related Causes

Opioid initiation or dose escalation leads to nausea in up to 50 % of patients; clinicians should anticipate this effect. 1
Cardiac and neurologic drugs such as digoxin, phenytoin, carbamazepine, and tricyclic antidepressants are associated with nausea; therapeutic drug monitoring is recommended when these agents are suspected. 2, 3
Chemotherapy and radiation therapy are major contributors to nausea, substantially affecting patients’ quality of life. 2, 3

Constipation, particularly in individuals receiving opioids, is a frequently overlooked but common precipitant of nausea. 4, 5, 6
Gastric outlet obstruction and bowel obstruction (mechanical or functional) must be excluded in the evaluation of nausea. 2, 3, 7
Gastritis and gastroesophageal reflux disease can be effectively treated with proton‑pump inhibitors or H₂‑receptor antagonists. 2, 3

Hypercalcemia represents a critical metabolic trigger for nausea and should be routinely assessed, especially in oncologic patients. 4, 5, 6
Nausea and vomiting of pregnancy typically begin at 4–6 weeks gestation and peak at 8–12 weeks; pregnancy should be considered in women of child‑bearing age. 8
Electrolyte disturbances and organ system failure are additional metabolic abnormalities that can precipitate nausea. 1

Central nervous system pathology—including increased intracranial pressure, tumors, or structural lesions—can manifest as nausea. 4, 5, 6
Cyclic vomiting syndrome is linked to triggers such as stress, sleep deprivation, hormonal fluctuations, and infections. 9

Anxiety and panic disorders may present with nausea; benzodiazepines can be useful for anxiety‑related nausea. 2, 3, 7

Clinicians should not attribute nausea to opioids without first evaluating for constipation, which is common and readily treatable. 4, 5, 6
In patients with cancer, hypercalcemia is frequently missed and must be actively screened for as a cause of nausea. 4, 6, 10
Mechanical bowel obstruction should not be overlooked, particularly in individuals with abdominal malignancies or a history of abdominal surgery. 4, 11, 6
Hot‑water bathing is not pathognomonic for cannabinoid hyperemesis syndrome; approximately 48 % of cyclic vomiting syndrome patients without cannabis exposure exhibit this behavior. 9

The NCCN guidelines identify chemotherapy and radiation therapy as major contributors to nausea and vomiting, with a substantial negative impact on patients’ quality of life【12】【13】【14】【15】【16】.
Cannabis exposure is linked to cannabinoid hyperemesis syndrome, cyclic vomiting syndrome, and cannabinoid withdrawal syndrome【17】.

Mechanical obstruction of the gastric outlet or the bowel must be actively excluded when evaluating nausea/vomiting【14】.

In pregnant individuals, nausea and vomiting typically begin at 4–6 weeks gestation and peak at 8–12 weeks【18】【19】.
Hyperemesis gravidarum is defined by severe nausea/vomiting that starts before 16 weeks gestation, accompanied by an inability to maintain normal oral intake and a marked limitation of daily activities【18】【19】.
Electrolyte disturbances—including low sodium, low potassium, and metabolic alkalosis—are recognized metabolic triggers of nausea/vomiting【18】.
Systemic organ failure, such as uremia, can precipitate nausea and vomiting【14】.
Thyroid dysfunction is present in approximately two‑thirds of individuals with hyperemesis gravidarum【18】.
Diabetes mellitus may lead to gastroparesis, contributing to nausea/vomiting【14】.

Central nervous system pathology (elevated intracranial pressure, brain metastases, tumors, or structural lesions) is a recognized cause of nausea/vomiting【14】.
Cyclic vomiting syndrome (CVS) is diagnosed when patients experience stereotyped episodes of acute vomiting lasting < 1 week, with ≥ 3 discrete episodes in the prior year and symptom‑free intervals between episodes【17】【20】.
Common CVS triggers include stress, sleep deprivation, hormonal fluctuations, infections, and a history of migraine【17】【20】.

Anticipatory nausea and vomiting—occurring as a conditioned response after prior negative chemotherapy experiences—has an incidence ranging from 18 % to 57 %【12】【13】【15】.

Hot‑water bathing is not pathognomonic for cannabinoid hyperemesis syndrome; about 48 % of CVS patients without cannabis exposure exhibit this behavior【17】.
Ketonuria should not be used as an indicator of dehydration or severity assessment in hyperemesis gravidarum【18】【19】.

Delayed‑onset nausea and vomiting after chemotherapy typically develop > 24 hours post‑infusion, reaching maximal intensity at 48–72 hours, especially with cisplatin regimens【12】【13】【15】.

Nausea and vomiting of pregnancy are defined as beginning before 16 weeks gestation; persistence of these symptoms beyond this gestational age should prompt evaluation for alternative causes. 21

If nausea, vomiting, or associated fatigue continue beyond 16 weeks or worsen after an initial improvement, clinicians should consider diagnoses other than typical pregnancy‑related changes. 21

Ondansetron is recommended as the first‑line antiemetic for symptomatic relief in patients presenting with nausea and vomiting because it does not cause sedation or akathisia, unlike alternative agents. 22

Intravenous fluid and electrolyte replacement should be administered to patients who have inadequate oral intake, dehydration, and weight loss. 22