Vomiting

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Key facts

Vomiting is a reflex that helps the body get rid of substances that may be harmful.
Gastroenteritis — an infection of the digestive tract — is one of the most common causes of nausea and sudden vomiting.
If vomiting is caused by an infection, such as gastroenteritis or food poisoning, it can often be managed at home if you stay hydrated.
Vomiting due to viral gastroenteritis usually clears up without any specific treatment within 2 days
Ongoing or recurrent episodes of vomiting should be investigated by your doctor.

What is vomiting?

Vomiting is the forceful ejection of the contents of the stomach and upper digestive system through the mouth. It is sometimes known as throwing up or being sick.

Vomiting is a reflex that helps the body get rid of substances that may be harmful. Most people will experience vomiting at some point.

This information concerns vomiting in adults and children over 12 years of age. See vomiting in children for information relating to children between 0 and 12 years.

What symptoms relate to vomiting?

Vomiting is accompanied by forceful contractions of the abdominal muscles. It is different from reflux or regurgitation which happen without any abdominal contractions.

Vomiting can sometimes be forceful — projectile vomiting can send the stomach contents more than a metre away.

Other symptoms that you may feel alongside vomiting are:

Nausea — before vomiting, a person usually experiences nausea. Nausea is the unpleasant feeling that you are about to vomit and is known as ‘feeling sick’. Once you have vomited, the feeling of nausea may ease or go away.
Mouthwatering — your mouth will often start to water if you are about to vomit.
Abdominal pain — pain anywhere between the bottom of your ribs and pelvis, and stomach cramps can both happen alongside vomiting.
Diarrhoea — diarrhoea and vomiting are a common combination of symptoms in gastroenteritis. They are both methods the body uses to get rid of harmful substances.
Dizziness — a feeling of light-headedness, unsteadiness or faintness.
Vertigo — a false sensation of movement or spinning, when the body is not moving.

Ongoing vomiting can lead to dehydration, where your body has lost more fluid than it has taken in, and doesn’t have enough water to function properly.

Retching is similar to vomiting, because it involves forceful stomach contractions. However, with retching, you will not bring up anything from your stomach.

What causes vomiting?

Vomiting can be a sudden isolated bout of vomiting (acute) that usually lasts less than 2 days or it can be part of a pattern of ongoing or recurring attacks (chronic). The underlying causes of vomiting are usually categorised into acute or chronic vomiting causes.

Acute vomiting causes

Some causes of sudden vomiting are serious, but one of the most common causes is viral gastroenteritis, which usually clears up without any specific treatment within 2 days. The following conditions can cause acute vomiting.

Gastroenteritis — an infection of the digestive tract — is one of the most common causes of nausea and sudden vomiting.
Food poisoning — some bacteria can cause food poisoning due to toxins (poisons) they secrete into food that is not stored properly.
Poisoning — this can cause nausea and vomiting, drowsiness, fits and seizures.
Motion sickness — this is more common in children than adults, but can also be the cause of vomiting in adults.
Alcohol — drinking excess alcohol frequently results in nausea and vomiting.
Post-operative — at least one-third of adults get nausea and vomiting after surgery, known as post-operative nausea and vomiting.
Gastrointestinal obstruction — an obstruction in your digestive tract will cause vomiting, often without nausea to start with.
Appendicitis — nausea and vomiting can both be caused by appendicitis.
Pancreatitis — inflammation of the pancreas usually causes abdominal pain, vomiting and fever.
Raised intracranial pressure — raised pressure in the skull is a medical emergency and can cause nausea and vomiting.
Meningitis — symptoms start suddenly and include vomiting, fever, a stiff neck, pain when looking at bright lights (photophobia) and sometimes a red or purple rash that doesn’t go away when gently pressed.
COVID-19 — nausea, diarrhoea and vomiting can all be symptoms of COVID-19.
Diabetic ketoacidosis — vomiting can be a symptom of diabetic ketoacidosis, where there is not enough insulin for the body to break down sugar.

Chronic vomiting causes

The following conditions can cause chronic vomiting.

Medicines — vomiting can be a side effect of some medicines, such as chemotherapy medicines used to treat cancer.
Radiation treatments — vomiting can be a side effect of radiation treatment.
Vitamins — high doses of vitamins can cause vomiting.
Pregnancy — Morning sickness is common during early pregnancy. It causes nausea and vomiting at any time of the day, but often in the morning.
Migraine — nausea and vomiting are common symptoms in the headache phase of a migraine.
Food allergies — coeliac disease can cause ongoing digestive symptoms, including vomiting.
Upper digestive tract disorders — vomiting after meals can be caused by GORD or gastrointestinal obstruction.
Gastroparesis — this is a delayed emptying of the stomach due to nerve damage. It can lead to nausea and vomiting after meals.
Kidney stones — nausea and vomiting are symptoms of kidney stones, along with gripping pain in the back.
Functional nausea and vomiting — this is the name given to chronic nausea and vomiting for which there is no clear medical cause.

When should I see my doctor?

If vomiting because of a simple case of gastroenteritis, it can often be managed at home without needing to see a doctor. But some underlying causes of vomiting can be more serious.

You should go to a hospital’s emergency department an ambulance if you:

vomit blood or a substance that looks like coffee grinds
vomit bile — this colours the vomit green
vomit faecal material (poo)
have severe or constant tummy (abdominal) pain
have a stiff neck and high temperature with or without photophobia (pain when looking at bright lights)
have a severe headache
have bleeding from your bottom (rectum) or bloody diarrhoea
have chest pain

Seek immediate medical attention, either from your doctor or from the emergency department, if you are vomiting and:

have a high temperature (fever)
have signs of dehydration
can’t take in more than a few sips of liquid or can’t keep water down
it continues for more than 48 hours

Make an appointment to see your doctor if you have been vomiting and have unexplained weight loss.

How is vomiting diagnosed?

Ongoing or recurrent episodes of vomiting should be investigated by your doctor. They will first want to assess you for dehydration.

Then, depending on your symptoms and the results of a physical examination, your doctor may suggest tests, including:

blood tests
urine tests
a pregnancy test

Sometimes, when it is difficult to find a cause for recurrent vomiting, investigations such as an endoscopy or a CT scan may help with diagnosis.

Your doctor may suggest referring you to a gastroenterologist or neurologist.

How is vomiting treated?

Treatment for vomiting depends on the underlying cause. Some causes of vomiting will need specific treatment, depending on how serious they are. Treatments include the following:

Vomiting and home care

If vomiting has an infectious cause, such as gastroenteritis or food poisoning, it can often be managed at home, as long as you stay hydrated.

Stay home to avoid passing the infection to others.
Drink plenty of clear fluids or oral rehydration solution to replace lost fluids — take small sips if you feel sick.
Avoid fruit juice, cordial and sugary drinks.
Avoid alcohol and caffeine.
Manage your diet until you get back to normal — eat bland foods, such as rice, pasta and crackers, and avoid fatty food.

Antiemetic medicines

Antiemetics are medicines that help prevent and treat nausea and vomiting. There are various types, depending on the underlying condition, and they work in different ways. Antiemetics are mostly prescription medicines.

Antiemetics can be used to treat vomiting that results from various causes, including the following:

Post-operative vomiting — this is vomiting after an operation. Antiemetics may also be given to prevent vomiting from happening in the first place.
Chemotherapy — vomiting is a common side effect of chemotherapy. Antiemetic medicines are often given to prevent or treat vomiting after chemotherapy.
Radiation treatment — this treatment to some areas of the body may cause vomiting. Antiemetic medicines may be given to prevent and treat nausea and vomiting caused by radiation.
Migraine — antiemetics can reduce nausea and vomiting caused by migraine.
Motion sickness — specific antiemetics that act on the vomiting centre of the brain may help with motion sickness.

Ginger

Ginger may help with nausea and vomiting due to several causes, including pregnancy, chemotherapy and motion sickness.

Dietary changes

Changes to your diet may help to reduce symptoms while doctors determine the cause of your vomiting. These include eating small meals, reducing fat content and avoiding spicy food or ingredients that cause you problems.

Surgery

Some causes of vomiting, such as appendicitis or bowel obstruction, will need emergency surgery.

What are the complications of vomiting?

Dehydration is one of the most serious complications of vomiting. If you lose too many fluids, you will lose electrolytes — minerals that are essential for your body to work properly. For this reason, you should take oral rehydration solution. Sip these slowly to avoid triggering more vomiting.

Ongoing vomiting may lead to weight loss. This is when a person can’t hold down their food, or the accompanying nausea results in them not wanting to eat, for a sustained period.

If you vomit within 2 hours of taking your oral contraceptive pill, you may not be protected from pregnancy. Refer to the instructions since you may need to use some other form of contraception, such as condoms, for the next 7 hormone pills.

A person can inhale vomit into their lungs, especially if they have ongoing vomiting. Breathing food or liquid into the lungs is referred to as aspiration and can cause pneumonia.

Violent vomiting can, very rarely, tear the lining of the oesophagus (food pipe).

Can vomiting be prevented?

The most common cause of vomiting — viral gastroenteritis — is very infectious and is mostly spread by contact with another person who has the illness.

Things you can do to stop the spread of gastroenteritis:

Wash your hands frequently, using a good handwashing technique.
Practice good food safety.
If a household member has gastroenteritis, they should not prepare food for other family members, and everyone should practice regular handwashing and good hygiene.
Anyone with gastroenteritis should not visit hospitals, aged care facilities, or swimming pools.
When cleaning up vomit, wear gloves, an apron and a mask. Dispose of it in a tied plastic bag and wash your hands afterwards. Clean the area with detergent and warm water.

Eating dry crackers or ginger may help alleviate vomiting caused by some conditions such as morning sickness or motion sickness.