Vomiting Dr Trisha Macnair Most people have experienced being sick, whether from an infection or food poisoning.

In this article

What is Vomiting? Symptoms

Causes and risk factors Treatment and recovery

Vomiting is being sick, or forcefully ejecting something from inside the stomach, up the gullet and out the mouth.

'Forcefully' is an important part of the definition because vomiting is different to posseting, which occurs in nearly all small babies and involves non-forcefully bringing back up small amounts of milk, often with swallowed air or 'wind', or regurgitation, which is non-forcefully bringing up larger amounts from the stomach.

Many children are sick just once and almost immediately announce they're hungry. But the vomiting may be repeated and undigested food seen in the vomit.

Worryingly, the vomit may be stained with bright green bile when there's underlying obstruction of the intestines.

A serious symptom is blood in the vomit

A serious symptom is blood in the vomit, which suggests damage to the delicate lining of the gullet or stomach. Extremely forceful (projectile) vomiting in the first few months of life is typical of pyloric stenosis.

Usually, the cause isn't very serious and occurs with feeding problems, dietary intolerance, gastroenteritis or travel sickness.

In babies and toddlers, vomiting may be caused by infections elsewhere in the body, such as the respiratory tract, ears or urinary tract.

When the vomiting is prolonged or repeated and the child is very ill, the cause may be more serious, such as an obstruction of the intestines (for example, from pyloric stenosis), kidney failure, coeliac disease or raised pressure inside the skull (intracranial pressure) because of a tumour or bleed.

Vomiting may be a childhood version of migraine. Some children vomit when they're upset, while in older children eating disorders can lead to intentional vomiting.

It's important to establish why a child is vomiting and to treat the cause.

It is important that a child who is vomiting is not allowed to get dehydrated. The best fluids to give a child are rehydration salts that can be bought at pharmacies (babies should continue to have milk). They should be made up according to the packet instructions and given in small but frequent amounts. Squash can be added to the fluid to make it taste nicer.

It does not matter if a vomiting child does not want to eat anything. In severe cases the child may need to go to hospital where intravenous fluids may be prescribed.

If the vomiting persists, is bright green or has blood in it, or if the child is generally unwell (with fever, rash, diarrhoea, headache, abdominal pain or drowsiness, for example) or seems dehydrated (has sunken eyes or fails to pass urine for more than six hours) then seek medical advice.

This article was last medically reviewed by Dr Orlena Kerek in March 2009