Nausea and Vomiting
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Nausea and Vomiting: Causes, Treatments, and When to Get Help in the UK
Key fact: Nausea and vomiting are among the most common symptoms seen in UK primary care — affecting everything from a 24-hour stomach bug to chronic conditions such as migraine and gastroparesis. Effective, UK-licensed treatments are available both over the counter and on prescription.
Nausea and vomiting are not diseases in themselves — they are protective reflex responses coordinated by the brain when it detects a potential threat to the body. That threat might be a gastrointestinal infection, an inner ear disturbance, the hormonal upheaval of early pregnancy, or the side effect of a medication. Because the underlying causes are so varied, choosing the right treatment depends on understanding which pathway is driving the symptom.
This guide brings together the full picture: the physiology of nausea, the most common UK triggers, every major treatment option from ginger root to prescription antiemetics, and clear red-flag criteria for when nausea and vomiting require urgent medical attention. Use the section links above to jump to whatever is most relevant to you right now.
What Is Nausea? Causes, Triggers, and Who It Affects
Nausea is the unpleasant subjective sensation of an impending urge to vomit. It is produced when the vomiting centre — a network of nuclei in the medulla oblongata of the brainstem — receives signals via one or more of four key input channels: the chemoreceptor trigger zone (CTZ, located in the area postrema outside the blood-brain barrier), the vestibular system (inner ear balance organs), the vagus nerve (carrying signals from the gut wall), and higher cortical centres (responding to pain, anxiety, anticipation, or sensory stimuli such as smell).
Understanding which input is dominant in a given patient is the key to selecting the right antiemetic. For example, drugs that block dopamine D2 receptors at the CTZ (such as domperidone and metoclopramide) work well for chemotherapy-induced or medication-related nausea, whereas drugs that block histamine H1 and muscarinic receptors in the vestibular pathway (such as cyclizine and hyoscine) work better for motion sickness and vertigo.
Who Is Most Affected?
Nausea can affect anyone, but certain groups are at disproportionate risk. Women of reproductive age experience nausea more frequently, driven largely by pregnancy-related hormonal changes and a generally heightened chemoreceptor sensitivity. People with a personal or family history of motion sickness are more susceptible to vestibular nausea. Individuals on polypharmacy — particularly opioids, antibiotics, or cytotoxic drugs — frequently experience drug-induced nausea. Those with functional gastrointestinal disorders, including irritable bowel syndrome (IBS) and gastroparesis, are chronically predisposed.
What Is Vomiting and When Is It Concerning?
Vomiting is the forcible expulsion of gastric contents through the mouth, coordinated by the vomiting centre via a rapid sequence: retrograde peristalsis moves stomach contents upward, the glottis closes to protect the airway, the abdominal muscles and diaphragm contract powerfully, and the lower oesophageal sphincter relaxes. It is a high-energy act with genuine protective value — expelling ingested toxins or pathogens — but becomes harmful when it is prolonged, severe, or masking a more dangerous underlying process.
Important: Acute vomiting lasting less than 24–48 hours in an otherwise healthy adult is usually self-limiting and caused by gastroenteritis or food poisoning. Vomiting lasting more than 48–72 hours, or accompanied by the red-flag features listed in the section below, requires same-day medical assessment.
The distinction between acute vomiting (sudden onset, short duration) and chronic or cyclical vomiting (recurring episodes over weeks or months) is clinically important. Chronic vomiting warrants investigation to exclude structural causes — including peptic ulcer disease, gastric outlet obstruction, or malignancy — rather than empirical antiemetic prescription.
Common Causes of Nausea and Vomiting in the UK
The most common causes seen in UK primary care are:
- Gastroenteritis / food poisoning — viral or bacterial gut infection; usually resolves within 24–72 hours
- Migraine — nausea affects ~80% of attacks; gastric stasis means oral medication may absorb poorly
- Vertigo and inner ear disorders — vestibular mismatch signals trigger the vomiting centre
- Pregnancy (NVP/morning sickness) — driven by rising hCG; affects 70–80% of pregnant women
- Motion sickness, medication side effects, anxiety — each activating different receptor pathways
For a full cause-by-cause clinical breakdown including dominant pathways and preferred antiemetic class for each: What causes nausea and vomiting? →
Over-the-Counter Anti-Sickness Options
Several antiemetics are available without a prescription in the UK. These are appropriate for mild-to-moderate nausea in adults where the cause is known (for example, travel sickness or a short-lived stomach upset) and there are no contraindications.
| Medicine | Brand Examples | Best For | Key Cautions |
|---|---|---|---|
| Cyclizine 50 mg | Valoid, Nausicalm | Motion sickness, vertigo-related nausea | Sedation; avoid in glaucoma, urinary retention |
| Hyoscine hydrobromide 300 mcg | Kwells, Joy-Rides | Motion sickness (especially sea travel) | Anticholinergic side effects; not in children under 3 |
| Cinnarizine 15 mg | Stugeron | Motion sickness, vestibular nausea | Sedation; avoid in Parkinson’s disease |
| Promethazine 10–25 mg | Phenergan, Avomine | Motion sickness, general nausea | Significant sedation; avoid in children under 2 |
| Ginger (standardised extract) | Various | Mild pregnancy nausea, post-operative nausea | Generally well tolerated; limited evidence for severe nausea |
Non-pharmacological approaches can also provide meaningful relief for mild nausea. Eating small, frequent, bland meals; staying hydrated with cold clear fluids; avoiding strong smells and greasy foods; applying acupressure at the P6 (nei guan) wrist point; and resting in a semi-upright position can all help. These measures are explored in full in our guide on how to stop feeling sick: home remedies and when to get treatment.
Prescription Antiemetics in the UK
When OTC medicines are insufficient — or where the cause of nausea requires a prescription-only drug — the following antiemetics are the most commonly used in UK clinical practice, aligned with NICE CKS and BNF guidance.
| Drug | Class / Mechanism | Typical Adult Dose | Main Indications | Key Safety Notes |
|---|---|---|---|---|
| Domperidone 10 mg | D2 antagonist (peripheral / CTZ) | 10 mg three times daily; max 7 days; max 30 mg/day | Nausea from gastric causes, migraine, gastroparesis, medication-induced | MHRA 2014: cardiac risk — avoid if QTc prolonged or cardiac history; do not use in pregnancy |
| Metoclopramide 10 mg | D2 antagonist (central + peripheral prokinetic) | 10 mg up to three times daily; short courses only (max 5 days) | Acute nausea, post-operative, migraine, gastroparesis | Risk of extrapyramidal reactions (especially young women); MHRA 2013 restriction |
| Prochlorperazine 5–10 mg | Phenothiazine D2 antagonist | 5–10 mg two to three times daily; 3 mg buccal tablet available | Vertigo-related nausea, labyrinthitis, nausea in palliative care | Extrapyramidal effects; avoid in hepatic impairment; sedating |
| Ondansetron 4–8 mg | 5-HT3 antagonist | 4–8 mg up to three times daily | Chemotherapy-induced, post-operative nausea; hyperemesis gravidarum (off-label) | Constipation; QT prolongation risk — ECG if cardiac risk factors; avoid in pregnancy unless specialist advice |
| Cyclizine 50 mg (POM) | H1 antihistamine + muscarinic antagonist | 50 mg up to three times daily | Vestibular nausea, vertigo, motion sickness, opioid-induced nausea, palliative care | Sedation; antimuscarinic effects; caution in heart failure (IV form) |
| Hyoscine butylbromide 20 mg | Antimuscarinic (antispasmodic) | 20 mg as needed | Nausea associated with bowel spasm or colic | Does not cross BBB; minimal CNS effects; not for motion sickness |
Choosing between antiemetics: The most effective antiemetic is one that targets the dominant receptor pathway driving the nausea. Vestibular nausea responds best to H1 antagonists; CTZ-mediated nausea responds to D2 antagonists; chemotherapy nausea often requires a 5-HT3 antagonist. Where the cause is unclear, a D2 antagonist (domperidone or metoclopramide) is a reasonable first choice for most acute nausea in adults.
Cyclizine vs Domperidone: Which Is Right for You?
| Cyclizine | Domperidone | |
|---|---|---|
| Mechanism | H1 antihistamine + anticholinergic | Dopamine D2 antagonist + prokinetic |
| Crosses blood-brain barrier | Yes — causes drowsiness | No — no drowsiness |
| Best for | Vertigo, motion sickness, PONV, pregnancy | Migraine nausea, gastroparesis, opioid-induced nausea |
| Availability | OTC (50mg) or prescription | Prescription only |
Full guides: Cyclizine: uses, dosing & how to get it → · Domperidone: uses, dosing & cardiac safety →
Nausea and Vomiting in Pregnancy
Nausea and vomiting of pregnancy (NVP) affects approximately 70–80% of pregnant women, typically beginning around week 6 and resolving by 16–20 weeks. Cyclizine is first-line treatment; severe hyperemesis gravidarum (HG) requires clinical assessment and may need IV rehydration.
Several medicines are safe in pregnancy — and several must be avoided. Getting the right advice matters here.
How to Get Anti-Sickness Treatment Without a GP Appointment
GP waiting times in the UK have lengthened considerably in recent years. For many people, waiting days or weeks for a GP appointment to address acute nausea — particularly from migraine, a stomach upset, or travel sickness — is neither practical nor necessary. Several legitimate routes to antiemetic treatment exist outside of traditional GP access.
NHS Pharmacy First (England)
From 2024, NHS Pharmacy First allows community pharmacists in England to assess and supply prescription-only medicines for several common conditions without a GP referral. While nausea is not currently a Pharmacy First consultation type, pharmacists can advise on OTC antiemetics and refer appropriately.
NHS 111 Urgent Clinical Assessment
NHS 111 (online or phone) can provide rapid clinical triage and, where appropriate, generate an urgent prescription via a connected GP or Emergency Department. Suitable for acute severe nausea where OTC options have failed.
Online Pharmacy with Pharmacist Prescribers
GPhC-registered online pharmacies staffed by pharmacist independent prescribers can conduct a clinical assessment and issue a prescription for domperidone, cyclizine, or other antiemetics where clinically appropriate. The process typically takes under 30 minutes and medicines can be dispatched the same day for next-day delivery.
GP eConsult or Online Triage
Most GP practices now offer online triage via eConsult or similar tools. A prescription request for a repeat antiemetic (for example, cyclizine for chronic vestibular symptoms) can often be processed within 24 hours without a face-to-face appointment.
Access Doctor: As a GPhC-registered online pharmacy (#9011198), Access Doctor’s pharmacist independent prescribers can assess your symptoms, confirm clinical suitability, and issue a prescription for domperidone or cyclizine if appropriate — all online, without a GP appointment.
How Long Does Nausea Last?
Duration depends almost entirely on the underlying cause — from under 24 hours for a simple stomach upset to persistent symptoms in pregnancy or chronic conditions such as gastroparesis.
Full duration timelines by cause: Nausea duration by cause →
When to See a Doctor
Most nausea and vomiting is self-limiting. Seek urgent care if you experience:
- Thunderclap headache, blood in vomit, or signs of stroke (facial drooping, arm weakness, slurred speech)
- Vomiting lasting more than 48–72 hours, or signs of dehydration (dark urine, dizziness on standing)
- Pregnancy and unable to keep any fluid down, or losing weight
Full red-flag checklist with emergency criteria: Red flag symptoms: when to seek urgent help →
Frequently Asked Questions about Nausea and Vomiting
What is the fastest way to stop nausea?
The fastest approach depends on the cause. For nausea driven by gastric or CTZ causes (gastroenteritis, migraine, medication), domperidone 10 mg taken as soon as symptoms begin works rapidly — typically within 30–60 minutes — and also accelerates gastric emptying. For vestibular causes (motion sickness, vertigo), cyclizine 50 mg is more effective. Immediate non-drug measures include sipping cold water or flat ginger ale, breathing fresh cool air, sitting upright, and applying P6 acupressure at the wrist. For a comprehensive overview of immediate relief strategies, see our guide on how to stop feeling sick.
Can I take cyclizine and domperidone together?
These two drugs work via different mechanisms (H1/muscarinic vs D2) and are not pharmacologically contraindicated together. However, combination use is unusual in routine practice — most episodes of nausea respond to one agent alone. Combined use should only be on the advice of a prescriber. The more important consideration is that domperidone has a cardiac caution (MHRA 2014) that must be assessed before prescribing.
Is it safe to take anti-sickness tablets every day?
This depends on the drug. Cyclizine can be taken regularly for chronic conditions such as vestibular disorders or when managing opioid-related nausea in palliative care. Domperidone, by contrast, should be used at the lowest effective dose for no more than 7 days per course due to its cardiac risk profile (MHRA 2014 review). Metoclopramide should be limited to 5-day courses. For chronic or recurrent nausea, a prescriber should assess whether ongoing antiemetic use is appropriate and investigate any underlying cause.
What causes nausea without vomiting?
Nausea without vomiting is extremely common and can arise from anxiety or stress (the most common cause in young adults), early pregnancy, GORD (gastro-oesophageal reflux disease), IBS, medication side effects (particularly SSRIs, metformin, antibiotics), or sensory triggers such as strong smells or heat. In contrast to true vomiting-centre activation, anxiety-related nausea typically does not respond well to antiemetics — treatment of the underlying anxiety is more effective.
What is the best antiemetic for migraine nausea?
Domperidone 10 mg is the preferred antiemetic for migraine-related nausea according to NICE CKS (Headache — migraine). It not only controls nausea at the CTZ but also reverses the gastric stasis that occurs during migraine attacks — a critical benefit because gastric stasis prevents oral painkillers (such as aspirin, ibuprofen, or triptans) from being properly absorbed. Domperidone should be taken at the very first sign of a migraine attack. For full detail, see: domperidone for migraine-related nausea: how it works in the UK.
Which anti-sickness medicine is safe in pregnancy?
Cyclizine 50 mg three times daily is the most widely recommended first-line antiemetic in pregnancy, with an extensive safety record and no established teratogenic risk. Promethazine is also widely used. Domperidone must be avoided in pregnancy as safety data are insufficient. Ondansetron is used only under specialist supervision for hyperemesis gravidarum where first- and second-line options have failed. See our pregnancy guide for full RCOG-aligned advice: nausea in pregnancy: morning sickness and hyperemesis treatment UK.
How do I know if my nausea is from anxiety?
Anxiety-related nausea tends to follow a characteristic pattern: it is triggered or worsened by stressful situations or anticipatory thoughts; it rarely leads to actual vomiting; it is often accompanied by other anxiety symptoms such as palpitations, sweating, or a sense of dread; and it improves when the stressor is removed. It does not typically respond to domperidone or other gut-acting antiemetics. Cognitive behavioural therapy (CBT), relaxation techniques, and in some cases treatment of the underlying anxiety disorder are the most effective approaches.
What is the difference between nausea from gastroenteritis and food poisoning?
Both cause acute nausea and vomiting, but they differ in onset and mechanism. Food poisoning typically presents within 1–6 hours of eating a contaminated meal (shorter if caused by preformed toxins such as Staphylococcal enterotoxin) and may affect multiple people who ate the same food. Viral gastroenteritis (stomach bug) usually develops 24–72 hours after exposure and spreads person-to-person. Both are largely self-limiting and treated with rehydration and symptom control.
Can vertigo cause severe nausea and vomiting?
Yes. Severe vertigo — particularly in acute vestibular neuritis, BPPV (benign paroxysmal positional vertigo), or Ménière’s disease — can cause highly distressing nausea and frank vomiting. The mechanism is an intense activation of the vestibular pathway, which sends conflicting signals to the vomiting centre. Cyclizine is the antiemetic of choice in these scenarios as it targets H1 and muscarinic receptors in the vestibular-cerebellar circuit. For full detail see: cyclizine for vertigo and nausea: how it works and how to take it.
What tablets are best for travel sickness?
The most effective OTC options for travel (motion) sickness in the UK are cyclizine (Nausicalm), hyoscine hydrobromide (Kwells), cinnarizine (Stugeron), and promethazine (Avomine). All four act on the vestibular pathway but differ in duration, side-effect profile, and suitability for children. Hyoscine is fastest-acting; cinnarizine lasts longest; cyclizine is well tolerated in most adults; promethazine is most sedating but effective for overnight travel. For a full comparison guide, see: motion sickness tablets: cyclizine, hyoscine, and travel sickness treatment UK.
When should I go to A&E for vomiting?
Go to A&E or call 999 immediately if vomiting is accompanied by sudden severe “thunderclap” headache, chest pain, signs of a stroke (FAST: face drooping, arm weakness, speech difficulty, time to call 999), vomiting blood or dark “coffee ground” material, altered consciousness, severe abdominal rigidity, or signs of anaphylaxis. For less acute concerns — persistent vomiting beyond 48 hours, dehydration, diabetic complications — contact NHS 111 or your GP urgently rather than waiting for a routine appointment.
References
- NICE CKS. Nausea and vomiting in pregnancy. Updated 2023.
- NICE CKS. Migraine. Updated 2023.
- NICE CKS. Labyrinthitis and vestibular neuritis. Updated 2022.
- NICE CKS. Gastroenteritis. Updated 2022.
- RCOG Green-top Guideline No. 69. The Management of Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum. 2024.
- MHRA. Domperidone: risks of cardiac side effects. Drug Safety Update, April 2014.
- MHRA. Metoclopramide: risk of neurological adverse effects — restricted dose and duration of use. Drug Safety Update, August 2013.
- BNF. Antiemetics — section on nausea and vomiting. Available via bnf.nice.org.uk.
- Gan TJ. Mechanisms underlying postoperative nausea and vomiting and neurotransmitter receptor antagonist-based pharmacotherapy. CNS Drugs. 2020;34(9):723–735.
- NHS. Vomiting in adults. Accessed May 2026.
- NHS. Vomiting and morning sickness in pregnancy. Accessed May 2026.
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting, stopping, or changing any medication. Domperidone, metoclopramide, prochlorperazine, and ondansetron are prescription-only medicines (POMs) in the UK and must be prescribed by a registered prescriber following a clinical assessment. Cyclizine is available both OTC and on prescription depending on the indication and pack size. In a medical emergency, call 999.
