Summary![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Nausea refers to an unpleasant sensation that is often localized to the abdomen and typically interpreted as an urge to vomit. Vomiting is the forceful oral expulsion of gastric contents. Although nausea and vomiting are the major symptoms of many gastrointestinal disorders, diseases of other organ systems should be considered during the workup. Nausea and vomiting can be due to early pregnancy, an adverse effect of medications or toxic ingestion, or a host of pathologies in other organ systems such as the CNS, endocrine, and vestibular systems. Nausea and vomiting may also be the manifesting symptoms of a functional disorder. Patients presenting with acute onset of recurrent vomiting should be evaluated for signs of dehydration and electrolyte and acid-base disorders, which should be corrected at the earliest opportunity. A thorough history and physical examination should be performed to narrow down the differential diagnoses and guide further diagnostic workup and treatment. Accompanying symptoms (e.g., fever, abdominal pain, headache) may provide clues as to the underlying disorder. Nausea and vomiting in children are not addressed here.
Management![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Evaluate and stabilize life-threatening complications before identifying and treating underlying causes of nausea and vomiting. The highest yield step to determine etiology is a thorough clinical evaluation.
Initial management [1][2][3]
-
ABCDE survey
- Consider airway management if airway protection is required (e.g., altered mental status).
- Turn actively vomiting patients with reduced mobility to the lateral decubitus position.
- Suction and clear debris from the oropharynx as needed.
- Consider rapid-sequence intubation for patients at high risk of aspiration.
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Immediate hemodynamic support if hypovolemic shock is present.
- Insert two large-bore peripheral IVs and administer IV fluid resuscitation
- If hemorrhagic shock is suspected (e.g., unstable patients with coffee-ground emesis): order type and crossmatched blood immediately.
- Respiratory support, e.g., oxygen therapy as needed
- Consider airway management if airway protection is required (e.g., altered mental status).
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Concurrent management
- Conduct a focused history and physical examination.
- Identify and treat potentially life-threatening sequela of vomiting, e.g.:
- Acid-base disorders
- Electrolyte imbalance (see “Electrolyte repletion”)
- Administer antiemetic therapy.
- Establish NPO status in patients with intractable or recurrent vomiting for whom a life-threatening cause of nausea and vomiting has not been ruled out.
- Perform targeted diagnostics (see “Diagnostic workup of nausea and vomiting”).
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Urgent specialty consult: as needed (See also “Disposition.”)
- Gastroenterology for patients with coffee-ground emesis/hematemesis or pancreatitis
- OB/GYN for hyperemesis gravidarum
- General surgery for patients with evidence of bowel obstruction
- Neurology and/or neurosurgery for patients with increased ICP or abnormal neurological examination
Further management
-
Supportive care: as needed
- NG tube placement, e.g., for suspected bowel obstruction with intractable vomiting
- Urinary catheter placement (e.g., Foley catheter) for urine output monitoring
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Treating the underlying etiology: Rule out life-threatening causes first.
- Conduct a detailed patient history and clinical examination.
- Consider the need for further diagnostic testing.
- Minimize or discontinue any contributing medications.
- If vomiting is due to ingestion of poisonous substances, see “Approach to the poisoned patient.”
Many herbal supplements can result in poisoning or cause herb-drug interactions that lead to nausea and vomiting (e.g., St John's Wort may cause serotonin syndrome); ask all patients specifically whether they use any herbal supplements. [4][5]
Consider whether antiemetics are necessary: Nausea may be self-limiting, and adverse effects of antiemetics include extrapyramidal symptoms due to metoclopramide and QT prolongation due to ondansetron. [1]
Red flags for nausea and vomiting
The following are red flags for life-threatening causes of nausea and vomiting.
-
Abdominal
- Coffee-ground emesis or hematemesis
- Feculent vomiting
- Melena
- Hematochezia
- Acute and/or severe abdominal pain
- Grossly distended or tympanitic abdomen
- Peritoneal signs
- Progressive dysphagia
- Unintentional weight loss
-
Neurological
- Altered mental status
- Focal neurological deficit
- Gait disturbances
- Meningeal signs, e.g.: stiff neck, severe headache
- Signs of increased ICP [6]
-
Pulmonary/cardiovascular
- Dyspnea
- Chest tightness
- Feeling of impending doom
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Other
- Recent head trauma
- Recent abdominal surgery
- Alcohol or other substance use
Immediately life-threatening causes
- Hemorrhagic stroke
- CNS infection (e.g., meningitis, encephalitis)
- Myocardial infarction
- Acute pancreatitis
- Bowel obstruction
- Bowel perforation
- Acute mesenteric ischemia
- Diabetic ketoacidosis
- Adrenal crisis (Addison crisis)
- Drug overdose/withdrawal
- Poisoning (e.g., ingestion of toxins)
Life-threatening diagnoses (e.g., meningitis, appendicitis, sepsis) can mimic self-limiting gastroenteritis. Avoid anchoring bias to prevent misdiagnosis and treatment delay.
Common complications of vomiting [1]
-
Metabolic
- Dehydration
- Contraction metabolic alkalosis
- Electrolyte disturbances [7]
- Ketosis [8]
- Pulmonary: aspiration pneumonitis and pneumonia
- Mechanical
Disposition [1]
-
Consider hospital admission in patients with any of the following:
- Severe vomiting refractory to antiemetic therapy
- Unremitting pain
- Significant metabolic abnormalities
- Evidence of an acute underlying condition or surgical pathology that requires in-hospital evaluation and treatment
- Insufficient response to IV fluids
- Inability to adhere to discharge instructions or attend outpatient follow-up
-
Consider discharge home if all of the following criteria are fulfilled:
- There are no life-threatening causes identified or other criteria for admission.
- The patient appears well, can tolerate oral clear liquids, and can adhere to discharge instructions.
- Outpatient follow-up is ensured.
Not all patients require IV hydration; oral rehydration therapy is effective and can be considered in patients without shock, refractory vomiting, or serious underlying pathology to reduce costs, admission rates, and complications. [10]
Diagnostics![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
There is no standard panel of tests to determine the etiology of nausea and vomiting because of the broad differential diagnosis. Choose diagnostic testing based on clinical suspicion.
Laboratory studies
Routine [2][3]
In patients with severe and sustained vomiting
- Blood gas analysis
- Urine ketones
Further diagnostic studies [2][3]
Diagnostic testing based on suspected system involvement | ||
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Laboratory studies | Imaging and other interventions | |
HEENT |
| |
Cardiopulmonary |
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Abdominal/pelvic |
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Neurological/psychiatric |
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Endocrine/metabolic |
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In patients with suspected gastroenteritis without signs of sepsis, it may not be necessary to do any diagnostic testing.
Rome IV diagnostic criteria for functional nausea and vomiting disorders [12][13]
Diagnosis of a functional nausea and vomiting syndrome requires symptom onset at least six months prior, with symptoms present for the previous three months.
-
Chronic nausea and vomiting syndrome (CNVS)
- Nausea at least once a week and/or one or more instances of vomiting per week
- Exclusion of self-induced vomiting, eating disorders, regurgitation, or rumination syndrome
- Routine investigations are negative for organic, systemic, or metabolic diseases that could explain the symptoms.
-
Cyclic vomiting syndrome (CVS)
- Acute episodes of vomiting, lasting less than one week
- A minimum of three episodes of vomiting in the prior year and two episodes in the past six months, with at least one symptom-free week in between the most recent episodes
- No vomiting outside of acute episodes (other milder symptoms may be present)
- Cannabinoid hyperemesis syndrome (CHS)
Life-threatening causes of nausea and vomiting![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Clinical features | Diagnostic findings | Acute management | |
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Acute coronary syndrome [14][15] |
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Acute pancreatitis [16][17][18] |
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Mechanical bowel obstruction [19][20][21][22] |
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DKA [23][24] |
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Meningitis [25][26][27] |
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Hyperemesis gravidarum [2][28][29][30] |
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Other causes of nausea and vomiting![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Clinical features | Diagnostic findings | Acute management | |
---|---|---|---|
Postoperative nausea and vomiting (PONV) [31][32] |
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Chemotherapy-induced nausea and vomiting (CINV) [33][33][34][35][36][37] |
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Uncomplicated first-trimester nausea and vomiting [2][28][29][30][38] |
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Infectious gastroenteritis [39][40][41][42][43] |
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Migraine [44] |
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Gastritis [47][48] |
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Gastroparesis [49] |
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Vestibular causes [51] |
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Nausea and vomiting are common adverse effects of numerous medications. When this occurs, use suitable alternatives or start with a lower dose to minimize symptoms.
Differential diagnosis![toggle arrow icon](https://manus-media.amboss.com/icons/chevron_up.svg)
Infectious causes
- HEENT
- Cardiopulmonary
-
Gastrointestinal
- Gastroenteritis (bacterial/viral)
- Infectious colitis
- Acute cholecystitis
- Acute cholangitis
- Acute hepatitis
- Liver abscess
- Acute appendicitis
- Genitourinary
- Neurologic
Noninfectious causes
- HEENT
- Cardiopulmonary
- Gastrointestinal
- Genitourinary
- Neurologic
-
Psychiatric
- Bulimia
- Anorexia nervosa
- Depression
- Anxiety disorders
- Functional
- Toxic-metabolic
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Drug-induced
- Antimicrobials
- Analgesics
- Cardiac drugs
- Anticonvulsants
- Antiparkinson medications
- Antidiabetics
- Antidepressants
- Recreational drug use
- Drug withdrawal
- Chemotherapeutic agents
- OCP
- Hormone replacement therapy
- Nicotine patches
- Sulfasalazine, mesalazine
- Iron supplements
- High-dose vitamins
- Cannabinoid hyperemesis syndrome