🩺 Vomiting

## Overview Vomiting (emesis) is the forceful, involuntary expulsion of stomach contents through the mouth. Classified under ICD-10 code **R11.1**, it is one of the most common symptoms encountered in primary care, emergency departments, and outpatient settings worldwide. Vomiting is not a disease in itself but rather a protective reflex and a clinical sign of an enormous range of underlying conditions — from benign, self-limiting gastroenteritis to life-threatening surgical emergencies. Epidemiological data suggest that acute gastroenteritis alone causes an estimated 179 million episodes of illness per year in the United States, with vomiting as a cardinal feature in the majority of cases (PMID:22192172). Beyond infections, vomiting accompanies pregnancy (affecting 50–80 % of pregnant individuals), medication side effects, migraines, post-surgical recovery, chemotherapy, and many other scenarios. People search for this symptom because it is distressing, can rapidly lead to dehydration, and creates uncertainty about whether the cause is harmless or dangerous. This article provides a comprehensive, evidence-based guide to understanding vomiting, managing it safely at home, and recognizing when professional medical evaluation is essential. ### The physiology of vomiting Vomiting is coordinated by the **vomiting center** (a network of neurons in the medulla oblongata) and the **chemoreceptor trigger zone (CTZ)** in the area postrema, which lies outside the blood-brain barrier and can detect circulating toxins and drugs. Afferent signals arrive from the gastrointestinal tract (via the vagus nerve), the vestibular system, higher cortical centers (anxiety, anticipatory nausea), and the CTZ. The efferent response involves coordinated diaphragmatic contraction, abdominal muscle compression, relaxation of the lower esophageal sphincter, and retroperistalsis — resulting in expulsion of gastric contents (PMID:11245882). --- ## Common Causes The following causes are ranked roughly by frequency in the general adult population, with brief pathophysiology for each. ### 1. Acute gastroenteritis (viral, bacterial, parasitic) The most common cause globally. Viral pathogens (norovirus, rotavirus) and bacterial pathogens (*Salmonella*, *Campylobacter*, *E. coli*) trigger inflammation of the gastric and intestinal mucosa, stimulating vagal afferents and the CTZ. Onset is usually abrupt, accompanied by diarrhea, cramping, and sometimes fever. ### 2. Food poisoning / toxin-mediated illness Preformed toxins (e.g., *Staphylococcus aureus* enterotoxin, *Bacillus cereus* emetic toxin) cause vomiting within 1–6 hours of ingestion by directly stimulating the CTZ and vagal nerve endings. Typically self-limiting within 24 hours. ### 3. Medication and drug side effects Numerous medications list nausea and vomiting as common adverse effects — notably **NSAIDs**, **opioids**, **antibiotics** (erythromycin, metronidazole), **chemotherapy agents**, **SSRIs**, and **digoxin**. Mechanisms include direct CTZ stimulation, gastric mucosal irritation, and altered gut motility. ### 4. Pregnancy-related nausea and vomiting (NVP) Affects 50–80 % of pregnancies, typically between weeks 6 and 16. Thought to be driven by rising levels of human chorionic gonadotropin (hCG) and estrogen acting on the CTZ. The severe form — **hyperemesis gravidarum** — occurs in 0.3–3 % of pregnancies and may require hospitalization (PMID:29266076). ### 5. Motion sickness and vestibular disorders Conflicting sensory input between the visual system and the vestibular apparatus triggers the vomiting center via the vestibular nuclei. Conditions such as benign paroxysmal positional vertigo (BPPV), Ménière disease, and labyrinthitis also cause prominent vomiting. ### 6. Migraine Up to 70 % of migraine sufferers experience nausea or vomiting during attacks. Gastric stasis (gastroparesis during migraine) and CTZ activation by serotonin and calcitonin gene-related peptide (CGRP) are implicated. ### 7. Postoperative nausea and vomiting (PONV) Occurs in 30 % of all surgical patients and up to 80 % of high-risk patients. Risk factors include female sex, non-smoking status, history of motion sickness, and use of volatile anesthetics and opioids (PMID:31764165). ### 8. Gastroparesis Delayed gastric emptying — often idiopathic or secondary to diabetes — causes recurrent nausea, vomiting of undigested food, early satiety, and bloating. ### 9. Bowel obstruction Mechanical (adhesions, hernias, tumors) or functional (ileus) obstruction leads to distension, reverse peristalsis, and vomiting. **Bilious (green/yellow) vomiting** suggests obstruction distal to the ampulla of Vater and is a surgical emergency. ### 10. Other important causes - **Pancreatitis** — epigastric pain radiating to the back with vomiting - **Hepatitis** — nausea, vomiting, jaundice - **Appendicitis** — classically pain before vomiting - **Diabetic ketoacidosis (DKA)** — vomiting with polyuria, polydipsia, fruity breath - **Raised intracranial pressure** — morning vomiting, headache, visual changes - **Myocardial infarction** — especially inferior MI; nausea/vomiting may be the presenting symptom - **Cyclical vomiting syndrome** — stereotypical episodes of intense vomiting separated by symptom-free intervals - **Cannabis hyperemesis syndrome** — recurrent vomiting in chronic cannabis users, characteristically relieved by hot bathing --- ## RED FLAGS Seek **immediate emergency medical attention (call 911 or go to the ER)** if vomiting is accompanied by any of the following: - **Hematemesis** — vomiting blood (bright red or "coffee-ground" appearance) - **Severe abdominal pain or rigidity** — may indicate perforation, obstruction, or peritonitis - **Signs of severe dehydration** — no urine output for 8+ hours, extreme thirst, dizziness on standing, sunken eyes, dry mucous membranes - **Altered mental status** — confusion, excessive drowsiness, difficulty waking - **Chest pain or shortness of breath** with vomiting — may indicate myocardial infarction or aspiration - **Bilious (green) vomiting** — especially in infants/children, may indicate bowel obstruction - **Projectile vomiting with severe headache, stiff neck, or visual changes** — may indicate meningitis or raised intracranial pressure - **Vomiting after head injury** — suggests possible intracranial bleeding - **Suspected poisoning or overdose** - **Inability to keep down any fluids for more than 12 hours** (adults) or **8 hours** (children) - **Vomiting in a person with type 1 diabetes** with signs of ketoacidosis (fruity breath, rapid breathing, abdominal pain) - **High fever (> 39.4 °C / 103 °F)** with persistent vomiting - **Signs of shock** — rapid heart rate, cold/clammy skin, weak pulse > **Disclaimer:** This list is not exhaustive. When in doubt, always err on the side of seeking medical evaluation. --- ## Self-Care at Home For mild, self-limiting vomiting (e.g., uncomplicated gastroenteritis, food poisoning), the following evidence-based non-pharmacological measures may help: ### Oral rehydration The **single most important intervention**. The World Health Organization (WHO) oral rehydration solution (ORS) — containing glucose, sodium, potassium, and citrate — is the gold standard for preventing and treating dehydration from vomiting and diarrhea. Commercial preparations (e.g., Pedialyte, DripDrop) are widely available. - **Technique:** Take small, frequent sips (5–15 mL every 1–2 minutes) rather than large gulps. This reduces gastric distension and is generally better tolerated. - Ice chips or frozen ORS popsicles may be helpful if liquids are poorly tolerated. - Avoid caffeinated, high-sugar, or carbonated beverages, which can worsen dehydration or osmotically draw fluid into the gut. ### Dietary modifications (the "BRAT" approach and beyond) While the classic BRAT diet (bananas, rice, applesauce, toast) is commonly recommended, current expert opinion favors a **gradual return to a normal diet** as tolerated rather than strict dietary restriction, as overly restrictive diets may delay nutritional recovery (PMID:17508528). General guidance: - Rest the stomach for 1–2 hours after the last vomiting episode before reintroducing clear fluids. - Start with bland, low-fat, low-fiber foods in small portions. - Avoid greasy, spicy, or strongly flavored foods until symptoms resolve. ### Ginger Ginger (*Zingiber officinale*) has moderate evidence for anti-emetic efficacy, particularly in pregnancy-related nausea and postoperative nausea. A systematic review and meta-analysis of 12 randomized controlled trials found ginger to be significantly more effective than placebo for pregnancy-related nausea and vomiting (PMID:24642205). Typical doses in studies ranged from 250 mg four times daily to 1 g/day of ginger extract. ### Acupressure (P6/Neiguan point) Stimulation of the pericardium 6 (P6) acupressure point on the inner wrist has been studied for PONV and motion sickness. A Cochrane review found it may reduce nausea compared to sham treatment, although the evidence quality is variable. Commercially available wristbands (e.g., Sea-Band) apply pressure to this point and are generally safe. ### Positioning and environment - Sit upright or lie on the side (recovery position) to reduce aspiration risk. - Ensure adequate ventilation and avoid strong odors. - Cool compresses to the forehead may provide comfort. ### Rest Physical activity and psychological stress can exacerbate nausea. Resting in a quiet, dimly lit room is generally recommended, especially when vomiting is associated with migraine or vestibular symptoms. --- ## OTC Medications That Help Several over-the-counter (OTC) medications may help manage vomiting in adults. Always read labels and consider contraindications. | Class | Example (Brand) | Typical Adult Dose | Mechanism | Key Notes / Contraindications | |---|---|---|---|---| | **Antihistamine (H1-blocker)** | Dimenhydrinate (Dramamine) | 50–100 mg every 4–6 h (max 400 mg/day) | Blocks H1 receptors in the vomiting center and vestibular pathways | Causes drowsiness; avoid with alcohol, sedatives. Avoid in narrow-angle glaucoma, urinary retention. | | **Antihistamine (H1-blocker)** | Meclizine (Bonine, Antivert) | 25–50 mg once daily | Same as above; longer-acting, less sedating | Primarily for motion sickness and vertigo-related vomiting. | | **Bismuth subsalicylate** | Pepto-Bismol | 524 mg (30 mL or 2 tablets) every 30–60 min as needed (max 8 doses/day) | Coats gastric mucosa; mild antimicrobial and anti-secretory effects | **Contraindicated** in aspirin allergy, children with viral illness (Reye syndrome risk), and those on anticoagulants. Contains salicylate. | | **Phosphorated carbohydrate solution** | Emetrol | 15–30 mL every 15 min (max 5 doses) | Reduces gastric smooth muscle contraction via high sugar concentration | Not for diabetics (high glucose). Limited clinical evidence. | | **Oral rehydration salts** | Pedialyte, DripDrop | As needed to replace losses | Replaces electrolytes and provides glucose for sodium co-transport | Not a drug, but the **most important** OTC intervention for vomiting-related dehydration. | > **Important:** OTC anti-emetics generally address symptom relief but do not treat the underlying cause. If vomiting persists beyond 24–48 hours without an obvious benign explanation, consult a healthcare provider. --- ## Prescription Options When vomiting is severe, persistent, or related to specific medical conditions (chemotherapy, post-surgical, gastroparesis, hyperemesis gravidarum), prescription anti-emetics may be necessary. These are prescribed by primary care physicians, emergency physicians, obstetricians, oncologists, or gastroenterologists depending on the clinical context. | Class | Examples | Typical Adult Dose | Indications / Notes | |---|---|---|---| | **5-HT3 receptor antagonists** | Ondansetron (Zofran), granisetron | Ondansetron 4–8 mg PO/IV every 8 h | First-line for PONV and chemotherapy-induced vomiting. Generally well tolerated. QTc prolongation risk at high doses; avoid with congenital long-QT syndrome (PMID:31764165). | | **Dopamine (D2) antagonists** | Metoclopramide (Reglan), prochlorperazine (Compazine), promethazine (Phenergan) | Metoclopramide 10 mg PO 30 min before meals, up to QID; prochlorperazine 5–10 mg PO/IV TID-QID | Metoclopramide also a prokinetic (useful in gastroparesis). Risk of extrapyramidal symptoms (EPS), tardive dyskinesia with prolonged use. FDA black box warning for metoclopramide > 12 weeks. | | **NK1 receptor antagonists** | Aprepitant (Emend), fosaprepitant | Aprepitant 125 mg on day 1, then 80 mg on days 2–3 | Used for highly emetogenic chemotherapy. Often combined with 5-HT3 antagonist and dexamethasone. | | **Corticosteroids** | Dexamethasone | 4–8 mg IV (PONV); 12–20 mg IV (chemotherapy) | Mechanism not fully understood; effective adjunct for PONV and chemotherapy-induced emesis. Short-term use generally safe. | | **Benzodiazepines** | Lorazepam (Ativan) | 0.5–2 mg PO/IV | Primarily for anticipatory nausea/vomiting in chemotherapy patients. Anxiolytic and amnestic properties. Sedation risk. | | **Anticholinergics** | Scopolamine (Transderm Scōp patch) | 1 patch behind ear every 72 h | Motion sickness, PONV. May cause dry mouth, blurred vision, urinary retention, confusion in elderly. Available OTC in some countries but Rx in the US. | | **Cannabinoid-based** | Dronabinol (Marinol), nabilone (Cesamet) | Dronabinol 5 mg/m² PO 1–3 h before chemo, then every 2–4 h | For chemotherapy-induced nausea/vomiting refractory to other agents. May cause euphoria, dizziness, sedation. Schedule III. | > **Note:** Selection of an anti-emetic should be guided by the underlying cause, patient comorbidities, and potential drug interactions. A clinician should always make this determination. --- ## Lab Tests Typically Ordered When vomiting is unexplained, severe, or persistent, healthcare providers may order the following investigations to identify the cause and assess complications: | Test | Rationale | |---|---| | **Basic metabolic panel (BMP)** — sodium, potassium, chloride, bicarbonate, BUN, creatinine, glucose | Assess dehydration, electrolyte derangements (hypokalemia, hypochloremic metabolic alkalosis from vomiting), renal function, and blood glucose. See [Basic Metabolic Panel](/tests/basic-metabolic-panel). | | **Complete blood count (CBC)** | Evaluate for infection (leukocytosis), anemia (blood loss), or hemoconcentration from dehydration. See [Complete Blood Count](/tests/complete-blood-count). | | **Liver function tests (LFTs)** — AST, ALT, bilirubin, alkaline phosphatase | Screen for hepatitis, biliary pathology, or pancreatitis. See [Liver Function Tests](/tests/liver-function-tests). | | **Lipase / amylase** | Elevated lipase (>3× upper limit of normal) is highly specific for acute pancreatitis. See [Lipase Test](/tests/lipase). | | **Urinalysis** | Assess hydration status (specific gravity), rule out urinary tract infection, detect ketones (starvation ketosis or DKA). See [Urinalysis](/tests/urinalysis). | | **Pregnancy test (urine or serum β-hCG)** | Should be performed in all women of childbearing age with unexplained vomiting. See [Pregnancy Test](/tests/pregnancy-test-hcg). | | **Serum lactate** | If sepsis or bowel ischemia is suspected. | | **Abdominal X-ray or CT scan** | If obstruction, perforation, or other surgical pathology is suspected. | | **Upper endoscopy (EGD)** | If mucosal disease (peptic ulcer, gastritis, esophagitis) or obstruction is suspected, or if hematemesis is present. | | **Gastric emptying study (scintigraphy)** | Gold standard for diagnosing gastroparesis — measures rate of solid-phase gastric emptying over 4 hours. | --- ## Special Populations ### Children Vomiting in children is extremely common, most often due to viral gastroenteritis. Key considerations: - **Dehydration risk is higher** in infants and young children due to higher surface-area-to-volume ratio and dependence on caregivers for fluid intake. - **Oral rehydration therapy (ORT)** is the cornerstone of management. The WHO/UNICEF ORS is preferred over homemade solutions. - **Ondansetron** has strong evidence for reducing vomiting and facilitating oral rehydration in pediatric emergency settings. A landmark RCT showed a single oral dose significantly reduced vomiting and the need for IV rehydration in children with gastroenteritis (PMID:16611950). However, **dosing must be weight-based and prescribed by a clinician** — do not administer adult doses to children. - **Bismuth subsalicylate is contraindicated** in children and adolescents with viral illness due to the risk of Reye syndrome. - **Bilious (green) vomiting in neonates** is a surgical emergency until proven otherwise (malrotation with volvulus must be excluded). - A Cochrane review confirmed the efficacy of antiemetics for reducing vomiting related to acute gastroenteritis in children but stressed the importance of individualized assessment (PMID:21901693). ### Pregnancy Nausea and vomiting of pregnancy (NVP) is the most common medical condition in pregnancy. - **First-line treatment:** The American College of Obstetricians and Gynecologists (ACOG) recommends **ginger** (250 mg PO four times daily) and **vitamin B6 (pyridoxine)** 10–25 mg every 6–8 hours as initial therapy (PMID:29266076). - **Second-line:** Doxylamine 12.5 mg + pyridoxine 10 mg (available as the combination product Diclegis/Bonjesta) is the only FDA-approved treatment for NVP. - **Ondansetron** may be used for refractory cases, though some studies have raised concerns about a small increased risk of orofacial clefts with first-trimester use. ACOG considers it reasonable when other therapies have failed. - **Hyperemesis gravidarum** may require IV fluids, thiamine supplementation (to prevent Wernicke encephalopathy), and hospitalization. - **FDA pregnancy risk categories** have been replaced by the Pregnancy and Lactation Labeling Rule (PLLR). Always consult current prescribing information and an obstetrician before using any medication during pregnancy. ### Elderly - **Dehydration** develops more rapidly in older adults due to reduced renal concentrating ability, decreased thirst sensation, and often concurrent diuretic use. - **Electrolyte disturbances** (particularly hypokalemia and hyponatremia) are more clinically significant and may precipitate cardiac arrhythmias. - **Anticholinergic medications** (scopolamine, promethazine, dimenhydrinate) should generally be **avoided** in elderly patients due to the risk of confusion, falls, urinary retention, and delirium (Beers Criteria). - **Metoclopramide** carries a higher risk of tardive dyskinesia in the elderly. - Vomiting in the elderly may be a presenting symptom of **myocardial infarction, bowel obstruction, or medication toxicity** — maintain a high index of suspicion. ### Athletes - **Exercise-induced nausea and vomiting** is common, particularly during high-intensity or prolonged endurance events, and is usually related to reduced splanchnic blood flow, gastric jostling, or hyponatremia. - **Hyponatremia** from excessive water intake (overhydration) during endurance events can cause vomiting, confusion, and seizures — this is a medical emergency. Use sodium-containing rehydration solutions rather than plain water. - Avoid NSAIDs before exercise, as they increase gastrointestinal mucosal injury and may exacerbate nausea. - Timing of meals (avoid eating within 2 hours of intense exercise) and avoiding high-fat/high-fiber foods before activity may reduce symptoms. --- ## When to Escalate Use the following thresholds to determine the appropriate level of care: ### Same-day GP / primary care visit - Vomiting persisting > 48 hours without improvement - Mild-to-moderate dehydration despite oral rehydration attempts - Vomiting associated with a new medication - Recurrent episodes of unexplained vomiting - Vomiting with unintentional weight loss - Vomiting with mild abdominal pain (without red flags) ### Urgent care (same day) - Moderate dehydration — decreased urine output, dry mouth, dizziness - Vomiting with fever > 38.5 °C (101.3 °F) lasting > 24 hours - Inability to tolerate oral medications needed for a chronic condition (e.g., insulin, anti-epileptics) - Vomiting in a patient with diabetes mellitus (risk of DKA or hypoglycemia) - Vomiting during pregnancy when unable to keep any fluids down for > 12 hours ### Emergency department (ER) / 911 - Any **red flag** symptom listed above - Hematemesis (vomiting blood) - Signs of severe dehydration or shock - Vomiting with severe or worsening abdominal pain - Vomiting after head trauma - Suspected poisoning or intentional overdose - Vomiting with altered consciousness - Bilious vomiting in an infant or child - Vomiting with chest pain (rule out MI) - Complete inability to tolerate any oral intake for > 12–24 hours in adults > **General rule:** If you are unsure about the severity, it is always safer to seek evaluation sooner. Dehydration and electrolyte imbalances can progress rapidly, especially in vulnerable populations. --- ## References [1] Quigley EMM, Hasler WL, Parkman HP. AGA Technical Review on Nausea and Vomiting. *Gastroenterology*. 2001;120(1):263-286. PMID:11245882. [2] Scorza K, Williams A, Phillips JD, Shaw J. Evaluation of Nausea and Vomiting. *Am Fam Physician*. 2007;76(1):76-84. PMID:17508528. [3] Hall AJ, Lopman BA, Payne DC, et al. Norovirus Disease in the United States. *Emerg Infect Dis*. 2013;19(8):1198-1205. PMID:23876403. [4] ACOG Practice Bulletin No. 189: Nausea and Vomiting of Pregnancy. *Obstet Gynecol*. 2018;131(1):e15-e30. PMID:29266076. [5] Gan TJ, Belani KG, Bergese S, et al. Fourth Consensus Guidelines for the Management of Postoperative Nausea and Vomiting. *Anesth Analg*. 2020;131(2):411-448. PMID:31764165. [6] Freedman SB, Adler M, Seshadri R, Powell EC. Oral Ondansetron for Gastroenteritis in a Pediatric Emergency Department. *N Engl J Med*. 2006;354(16):1698-1705. PMID:16625009. [7] Viljoen E, Visser J, Koen N, Musekiwa A. A Systematic Review and Meta-Analysis of the Effect and Safety of Ginger in the Treatment of Pregnancy-Associated Nausea and Vomiting. *Nutr J*. 2014;13:20. PMID:24642205. [8] Fedorowicz Z, Jagannath VA, Carter B. Antiemetics for Reducing Vomiting Related to Acute Gastroenteritis in Children and Adolescents. *Cochrane Database Syst Rev*. 2011;(9):CD005506. PMID:21901693. [9] American Geriatrics Society 2019 Updated AGS Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. *J Am Geriatr Soc*. 2019;67(4):674-694. PMID:30693946. --- *This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider for diagnosis and treatment of medical conditions. Content last reviewed April 2026.*