Nausea and vomiting

Last updated: July 5, 2023

Summary

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

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.
- 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
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”).
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
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
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

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]

CBC
ESR
Serum glucose
BMP
LFTs
Beta hCG urine test

In patients with severe and sustained vomiting

Blood gas analysis
Urine ketones

Further diagnostic studies ^[2]^[3]

Diagnostic testing based on suspected system involvement
	Laboratory studies	Imaging and other interventions
HEENT	N/A	Pure tone audiometry Perimetry visual fields Gonioscopy and tonometry Tilt table test
Cardiopulmonary	Troponin Digoxin level Theophylline level	ECG TTE X-ray chest (upright)
Abdominal/pelvic	Lipase, amylase Coagulation studies (e.g., INR, PT) CRP Urinalysis Stool culture Stool ova and parasites Stool leukocytes FOBT C. difficile toxin PCR Stool viral PCR H. pylori antigen	X-ray abdomen (upright and supine) X-ray chest (upright) Ultrasound abdomen (complete) or POCUS Duplex ultrasound of the pelvis (♀)/scrotum (♂) Transvaginal ultrasound CT abdomen and pelvis with IV contrast ^[11] MRI abdomen and pelvis Upper gastrointestinal endoscopy Consider the following in patients with suspected gastric and esophageal motility disorders. Barium swallow Barium meal and small bowel follow-through Gastric emptying scintigraphy
Neurological/psychiatric	Toxicology screen Salicylate level	MRI brain CT head Lumbar puncture
Endocrine/metabolic	TSH, free T₃, T₄ PTH levels AM cortisol, ACTH HA1c	N/A

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)
- Onset, duration, and frequency of episodes similar to CVS
- Associated with chronic cannabis use
- Sustained cessation of cannabis use resolves vomiting

Life-threatening causes of nausea and vomiting

	Clinical features	Diagnostic findings	Acute management
Acute coronary syndrome ^[14]^[15]	Heavy, dull, pressure/squeezing sensation Substernal pain with radiation to left shoulder Nausea, vomiting Diaphoresis, anxiety Dizziness, lightheadedness, syncope Pain may improve with nitroglycerin.	ECG: nonspecific changes, ST-segment elevation/depression, T-wave inversions, Q waves Increased or normal troponin TTE: hypokinesis, regional wall motion abnormalities	See the “Acute management checklist for STEMI” and “The acute management checklist for NSTEMI/UA.”
Acute pancreatitis ^[16]^[17]^[18]	Severe epigastric pain that radiates to the back Nausea, vomiting Epigastric tenderness, guarding, rigidity Upper abdominal pain Hypoactive bowel sounds History of gallstones or alcohol use	↑ Lipase, amylase Abdominal ultrasound: pancreatic edema, peripancreatic fluid, gallstones Abdominal CT with IV contrast : pancreatic edema, peripancreatic fat stranding, gallstones	See the “Acute management checklist for acute pancreatitis.”
Mechanical bowel obstruction ^[19]^[20]^[21]^[22]	Colicky abdominal pain Obstipation/bloating Progressive nausea and vomiting (late finding) Diffuse abdominal distention, tympanic abdomen, collapsed rectum on DRE Tinkling bowel sounds History of abdominal surgery	X-ray abdomen Dilated bowel loops proximal to the obstruction Rectal air shadow absent Multiple air-fluid levels CT abdomen with IV contrast Similar findings as on x-ray Transition point at site of obstruction	See the ”Acute management checklist for mechanical bowel obstruction.”
DKA ^[23]^[24]	Polyuria, polydipsia Nausea and vomiting Signs of volume depletion Altered mental status, coma	Hyperglycemia, high anion gap metabolic acidosis, ketonuria/ketonemia	See the “Acute management checklist for hyperglycemic crises.”
Meningitis ^[25]^[26]^[27]	Classic triad: fever, headache, and neck stiffness (nuchal rigidity) Meningism (e.g., photophobia) Dull, diffuse (holocephalic) headache that worsens over hours/days Altered mental status Nausea, vomiting Seizures	↑ WBC, ↑ procalcitonin (if bacterial) CSF analysis Bacterial: WBC ≥ 1000 cells/μL (predominantly neutrophils), elevated protein, low glucose, positive gram stain Viral: WBC 10-500 cells/μL (predominantly lymphocytes), normal-elevated protein, normal glucose	See the “Acute management checklist for meningitis.”
Hyperemesis gravidarum ^[2]^[28]^[29]^[30]	Severe, persistent nausea and vomiting associated with pregnancy Weight loss Dehydration	Ketonuria Electrolyte and acid-base abnormalities	See the “Acute management checklist for hyperemesis gravidarum.”

Other causes of nausea and vomiting

	Clinical features	Diagnostic findings	Acute management
Postoperative nausea and vomiting (PONV) ^[31]^[32]	Nausea and/or vomiting within the first 24–48 hours of surgery	Clinical diagnosis	See the “Acute management checklist for PONV.”
Chemotherapy-induced nausea and vomiting (CINV) ^[33]^[33]^[34]^[35]^[36]^[37]	Nausea and/or vomiting related to recent chemotherapy	Clinical diagnosis	See “Treatment of CINV.”
Uncomplicated first-trimester nausea and vomiting ^[2]^[28]^[29]^[30]^[38]	Nausea and vomiting associated with early pregnancy Presumptive signs of pregnancy	Urine and serum beta hCG positive Abdominal or transvaginal ultrasound: gestational sac or embryo, fetal heartbeat	See the “Acute management checklist for uncomplicated nausea and vomiting of pregnancy.”
Infectious gastroenteritis ^[39]^[40]^[41]^[42]^[43]	Fever Nausea, vomiting Diarrhea, abdominal pain Blood in stool Normal abdominal examination Exposure history	Clinical diagnosis Stool analysis: fecal leukocytes	See the “Acute management checklist for infectious gastroenteritis.”
Migraine ^[44]	Unilateral headache with pulsating, boring/hammering pain Nausea, vomiting Hyperacusis Photophobia, phonophobia Preceding aura	Clinical diagnosis ^[44] Neuroimaging: typically normal findings ^[45]^[46]	See the “Acute management checklist for migraine headache.”
Gastritis ^[47]^[48]	Dyspepsia Postprandial fullness, early satiety Bloating Epigastric tenderness without peritoneal signs	EGD with biopsy See also “Approach to dyspepsia.”	See “Treatment” in “Gastritis.”
Gastroparesis ^[49]	Postprandial epigastric pain Early satiety Nausea and vomiting of partially digested food Epigastric tenderness and distention on abdominal examination Weight loss	Gastric emptying scintigraphy (gold standard) ^[50]	First-line: dietary modification Pharmacological therapy First-line: metoclopramide ^[49] Second-line: Erythromycin ^[49] Treatment of refractory gastroparesis PEG placement Gastric stimulators or pacemakers
Vestibular causes ^[51]	Acute vestibular syndrome Vestibular neuritis: severe vertigo, recent URI Labyrinthitis: severe vertigo and cochlear symptoms BPPV: vestibular syndrome triggered by movement Meniere's disease: episodic vestibular syndrome, unilateral cochlear symptoms, and aural fullness See also “Causes of peripheral vertigo.”	Vestibular neuritis and labyrinthitis: Negative HINTS examination BPPV: Positive provoking maneuvers for BBPV Meniere's disease: See “Diagnostic criteria for Meniere disease” See also “Approach to vertigo.”	Consider vestibular suppressants, e.g.,: Meclizine Scopolamine Treat the underlying cause (e.g., Epley maneuver for BPPV).

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

Infectious causes

HEENT
- Acute otitis media
- Acute labyrinthitis
Cardiopulmonary
Gastrointestinal
- Gastroenteritis (bacterial/viral)
- Infectious colitis
- Acute cholecystitis
- Acute cholangitis
- Acute hepatitis
- Liver abscess
- Acute appendicitis
Genitourinary
- Urinary tract infection (e.g., cystitis, pyelonephritis)
- PID
- Tubo-ovarian abscess
- Prostatitis
- Orchitis
- Epididymitis
Neurologic

Noninfectious causes

HEENT
- Peripheral vertigo
- Ménière disease
- BPPV
- Labyrinthitis
- Vestibular neuritis
- Acoustic neuroma
- Angle-closure glaucoma
Cardiopulmonary
- Myocardial infarction
Gastrointestinal
- GERD
- PUD
- Acute gastritis
- Gastric outlet obstruction
- Gastroparesis
- Bowel obstruction
- Acute mesenteric ischemia
- Chronic mesenteric ischemia
- Intussusception
- Malrotation
- IBD
- IBS
- Acute pancreatitis
- Biliary colic
- Noninfectious hepatitis
Genitourinary
Neurologic
- Migraine
- Cluster headaches
- Brain tumor
- Intracranial hemorrhage (acute/chronic)
- Ischemic stroke
- Hydrocephalus
- Seizure disorder
Psychiatric
Functional
Toxic-metabolic
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

Start your trial, and get 5 days of unlimited access to over 1,100 medical articles and 5,000 USMLE and NBME exam-style questions.

Start free trial

Evidence-based content, created and peer-reviewed by physicians. Read the disclaimer