Vomiting is uncomfortable, occasionally a sign of something serious, and a major risk for dehydration in babies, young children, older adults, and pregnancy. Most vomiting is short-lived and settles with rest and small sips of fluid. This page helps you tell when self-care is enough and when to seek a doctor.
Emergency
Call triple zero (000) or go to your nearest emergency department if you are vomiting and have:
- vomit with blood in it, or that looks like coffee grounds
- luminous green or bile-green vomit
- black, tarry or bloody stools
- severe abdominal pain, or a hard, swollen belly
- chest pain
- a severe headache, stiff neck, or a rash that does not fade when pressed
- confusion, drowsiness or fainting
- signs of severe dehydration, such as passing very little or no urine, or feeling faint when you stand up
- vomiting after a head injury
- a chronic disease, such as diabetes, and you cannot keep fluids or your usual medicines down
Babies, children and people at higher risk
Babies, young children, older adults, pregnant people and people with long-term health conditions can become dehydrated quickly. Call 000 or go to an emergency department if a baby or child is drowsy or floppy, has not had a wet nappy or passed urine for 6 hours or more, or has luminous green or bile-green vomit. **Poisoning: call the Poisons Information Centre on 13 11 26 (24 hours). Call 000 if the person is unwell or hard to wake.
Key points
- Vomiting is a symptom, not a disease. The cause matters more than the act of vomiting itself.
- Most vomiting is caused by a stomach bug, food poisoning, motion sickness, pregnancy, migraine, or medication side effects.
- The biggest immediate risk is dehydration, especially in babies, young children, older adults, and pregnancy.
- Some causes (head injury, a blocked bowel, appendicitis, severe infection, diabetic complications (ketoacidosis), raised pressure in the brain, poisoning) are serious and need urgent care.
- Self-care focuses on small, frequent sips of fluid and avoiding triggers that worsen nausea.
What vomiting is
Vomiting is the forceful emptying of stomach contents through the mouth. It is controlled by a coordinated reflex involving the brainstem, the gut, and the diaphragm. It is preceded by nausea (the unpleasant feeling that you might vomit), retching, and a quickened heart rate.
Vomiting once or twice during a viral illness is not the same as repeated, persistent vomiting. The pattern, the colour, what comes with it, and how long it has been going on all matter for working out the cause.
Common causes
The most common causes of vomiting are:
- Gastroenteritis (a stomach bug, often with diarrhoea) and food poisoning
- Pregnancy (morning sickness or a severe form of vomiting and nausea known as hyperemesis gravidarum)
- Motion sickness
- Migraine
- Medication side effects (e.g. antibiotics, opioids and chemotherapy)
- Excessive alcohol
- Anxiety
- Anaesthetic and surgery (post-operative nausea)
- Reflux disease
Less common but more serious causes include:
- Bowel obstruction (green (bile) vomit, or vomiting with a swollen belly and being unable to pass wind or stool)
- Appendicitis (pain, fever, vomiting; see our stomach pain article)
- Pancreatitis (severe upper abdominal pain, vomiting)
- Gallstones
- Diabetes complications known as diabetic ketoacidosis (vomiting, deep breathing, fruity breath, drowsiness, especially in type 1 diabetes)
- Raised pressure in the brain (vomiting, severe headache, drowsiness, often early morning)
- Head injury
- Inner ear problems (severe vertigo with vomiting)
- Poisoning, overdose, or chemical exposure
In babies and young children, persistent forceful vomiting in the first 6 to 12 weeks of life can be pyloric stenosis (a condition where the muscular valve at the bottom of the stomach does not work properly). Luminous green or bile-green vomit in any baby or child needs emergency review for bowel obstruction.
Pregnancy
Nausea and vomiting are very common in early pregnancy (morning sickness). This usually improves by 16 to 20 weeks. Treatment is small, frequent meals, ginger, and pregnancy-safe medications when needed.
Severe pregnancy vomiting (hyperemesis gravidarum) causes weight loss, dehydration, and electrolyte problems. It needs medical assessment and sometimes admission for IV fluids and medication. Treatment is step by step, starting with vitamin B6 and other pregnancy-safe anti-nausea medicines, under medical supervision.
Recognising dehydration
Dehydration is the main risk of any persistent vomiting.
In adults, watch for: dark urine, dry mouth, dizziness on standing, weak or fast pulse, drowsiness, confusion. Urinating less often than usual is a useful sign.
In children, watch for: fewer wet nappies, dry mouth, sunken eyes, no tears when crying, drowsy or floppy, fast breathing, cool hands and feet.
Severe dehydration in any age group is a medical emergency.
Treatment and self-care
Adults
For most short-lived vomiting:
- Take small, frequent sips of water or an oral rehydration solution, such as Hydralyte or Gastrolyte. These come as ready-made drinks, ice blocks, powders or dissolvable tablets, and are sold at pharmacies and supermarkets without a prescription. Even a teaspoon every 5 to 10 minutes is enough at first
- Avoid solid food until vomiting has settled, then start with plain foods (toast, banana, rice, plain crackers)
- Avoid sugary drinks (cola, juice, sports drinks) as the main fluid in moderate to severe vomiting; the high sugar content can worsen things
- Avoid the smells, foods, or activities that triggered the nausea
- A pharmacist can advise on motion sickness medicine. Other anti-nausea medicines are usually only used with medical advice
Babies and children
- Continue breastfeeding or formula feeding in small, frequent amounts
- Offer small, frequent sips of fluid by syringe, teaspoon or cup between feeds. Ask a pharmacist which oral rehydration products are suitable for your child's age
- Avoid sweet drinks
- See a doctor early if a child is not keeping fluids down or showing signs of dehydration
When anti-nausea medicines are used
Anti-nausea medicines can help, but they are not usually needed for an ordinary stomach bug. A doctor may prescribe one for specific situations, such as migraine, pregnancy, after surgery or severe gastroenteritis.
In children, an anti-nausea medicine is sometimes given in a clinic or hospital to stop vomiting and avoid a drip. Do not give children anti-nausea medicine at home unless a doctor has advised it.
When to see a doctor
If you have any of the signs in the emergency box at the top of this page, call triple zero (000) or go to your nearest emergency department.
Get an urgent GP appointment, or call healthdirect on 1800 022 222 for advice, if you are vomiting and:
- you cannot keep fluids down, or have signs of dehydration
- you have a high fever
- it has lasted more than 48 hours (24 hours in a child)
- you have a weakened immune system
- you are pregnant and cannot keep food or fluids down
- a baby under 6 months is vomiting repeatedly, or a young baby has forceful (projectile) vomiting
- it started after a new medicine
See a GP if:
- vomiting keeps coming back
- you have lost weight without trying
How Doccy doctors can help
A Doccy consultation can help if you have mild vomiting, for example from a stomach bug, and none of the warning signs on this page. A Doccy consultation can:
- provide a medical certificate if you need time off work or study, or a carer's certificate if you are looking after someone who is unwell
- provide a special consideration letter if illness has affected a university assessment or deadline
- prescribe anti-nausea medicine, including for morning sickness, if it is appropriate
- continue a prescription for anti-nausea medicine you already take
A Doccy consultation is not suitable if you have any of the signs in the emergency box, signs of dehydration, or a baby or young child who is vomiting. A doctor cannot examine you remotely, so these need to be assessed in person.
Resources and support
healthdirect: health information and a 24-hour nurse advice line on 1800 022 222; healthdirect.gov.au.
Pregnancy, Birth and Baby: pregnancy nausea and infant feeding, 1800 882 436; pregnancybirthbaby.org.au.
The Royal Children's Hospital Melbourne, Kids Health Info: vomiting and gastro in children; rch.org.au/kidsinfo.
Poisons Information Centre: 13 11 26 (Australia-wide, 24 hours).
Better Health Channel (Victoria): gastroenteritis information; betterhealth.vic.gov.au.
These services and websites can provide extra information, but they do not replace advice from your own doctor.
- healthdirect. Vomiting. 2024. https://www.healthdirect.gov.au/vomiting
- Better Health Channel (Victoria). Vomiting in adults. 2024. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/vomiting-adults
- Better Health Channel (Victoria). Children and vomiting. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/children-and-vomiting
- The Royal Children's Hospital Melbourne. Kids Health Info: Gastroenteritis. 2024. https://www.rch.org.au/kidsinfo/fact_sheets/Gastroenteritis_gastro/
- Pregnancy, Birth and Baby. Morning sickness and pregnancy nausea. 2024. https://www.pregnancybirthbaby.org.au/morning-sickness
- NICE Clinical Knowledge Summaries. Nausea and vomiting in adults. 2024. https://cks.nice.org.uk/topics/nausea-vomiting-in-adults/