Vomiting, or throwing up, is the sudden emptying of your stomach’s contents. Medically known as emesis, vomiting is rarely serious, although it can harm the very young and the very old.

By Wallace Health I Medically reviewed by Adrian Roberts.
Page last reviewed: October 2018 I Next review due: October 2023


Vomiting has many possible causes but it is often a symptom of a stomach bug (gastroenteritis).

Vomiting tends to only last for 48 hours and is often accompanied by feeling sick (nausea). It can usually be treated at home simply by drinking lots of fluids and other simple remedies. 

If you are vomiting for several days, see your GP, as vomiting can be a symptom of an underlying condition. Frequent vomiting can make you dehydrated and if left untreated, this can be life-threatening.

Vomiting causes

Vomiting is usually your stomach’s way of responding to or getting rid of harmful substances, including bacteria, viruses, poison, excess alcohol and contaminated food. 

In adults, the most common cause of projectile vomiting and diarrhoea is gastroenteritis — an infection of your stomach with a bacteria or virus that usually resolves in a few days. Often the virus is contracted through contact with someone who is infected with norovirus or through eating food contaminated with harmful bacteria, such as Campylobacter (food poisoning). By vomiting, your body is trying to eject whatever is at the root of the problem.

Vomiting can also be triggered by your brain. The splitting pain of a headache or migraine is often accompanied by vomiting. The viral infection labyrinthitis, which affects the inner ear, can cause dizziness, feeling as if you are spinning, lack of balance and vomiting. The inner ear is also responsible for motion or travel sickness, which causes nausea and vomiting.

Vomiting in pregnant women

Many pregnant women find that they have morning sickness, which involves nausea and/or vomiting, especially during the first trimester of pregnancy (weeks 1-12). Although it is called morning sickness, it can occur throughout the day. It usually goes away during the second trimester at around 16-20 weeks. On rare occasions, morning sickness is so severe it causes dehydration and hyperemesis gravidarum, a serious condition requiring hospital treatment.

Other causes of vomiting

Certain serious illnesses can cause vomiting even though they do not directly affect your gastrointestinal system eg heart attack, pneumonia and sepsis. 

Side effects of certain medications can also cause vomiting, including antibiotics, chemotherapy, radiotherapy and general anaesthetics. Noxious stimuli can similarly cause vomiting — this includes extreme emotional shock, intense pain or certain smells and sounds. 

In rare cases in infants, vomiting may be caused by pyloric stenosis, a condition where the connection (pylorus) between the stomach and small intestine narrows, preventing food from passing through.

There are many different reasons for vomiting, which usually need little if any, medical attention. If you have frequent vomiting and none of the reasons above explains your vomiting, you may have cyclic vomiting syndrome. 

Cyclic vomiting syndrome

This refers to bouts of vomiting for up to 10 days with no apparent cause and usually occurs in children. Other symptoms include nausea and fatigue.

Left untreated, it can cause bouts of vomiting several times a year and lead to serious complications, such as: 

    • A tear in your gullet (oesophagus)
    • Dehydration
    • Oesophagitis — inflammation of your gullet
    • Tooth decay

Vomiting emergencies

Vomiting can sometimes be a warning sign of a serious medical emergency. Seek urgent medical attention if you are vomiting and have:

  • A stiff neck, a rash, a high temperature and an aversion to bright light — these are possible symptoms of meningitis
  • A sudden and intense headache — this may be a warning of a brain tumour or the result of a brain injury
  • Blood in your vomit (haematemesis) — you may vomit a lot of red blood, spit up dark blood or cough up a brown substance that looks like coffee grounds (clotted blood), alongside feeling dizzy; this can be caused by: 
    • A bleeding stomach ulcer 
    • A severely inflamed stomach lining
    • Burst blood vessels
    • Certain types of cancer
  • Fever
  • Severe chest pain — this may be a sign of a heart attack
  • Sudden, severe abdominal pain — your appendix may be about to burst or have burst (appendicitis)

You should also seek urgent medical attention if you have been vomiting for more than a day and it isn't getting better, you think you have food poisoning or you think you have swallowed something poisonous.

Talk to your doctor if you’re concerned about symptoms

You can book an appointment with a Spire private GP today.

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Vomiting complications

The most common complication of vomiting is dehydration as vomiting makes you lose fluids as well as food. Symptoms of dehydration include:

  • A dry mouth
  • Confusion
  • Darker urine
  • Fatigue
  • Headaches
  • Reduced urination

Untreated dehydration can be life-threatening in infants, young children and the elderly. 

Frequent vomiting can also cause malnutrition. When your body is unable to keep food down, your gut isn't able to absorb enough of the nutrients your body needs to stay healthy. 

Getting a diagnosis for vomiting

In most cases, you’ll stop vomiting after one or two days of illness. If necessary, you should be able to treat your vomiting with simple remedies or over-the-counter medication.

However, if your child is vomiting, dehydrated and has a high temperature, contact your GP urgently or seek medical attention. In addition, you should visit your GP or seek medical attention if:

  • You’re bringing up green or yellow vomit — this may be a sign of a blockage in your bowel
  • You’re diabetic and you’ve been vomiting a lot — prolonged vomiting can cause problems with your blood sugar levels
  • You’re severely dehydrated — symptoms include confusion, light-headedness, a racing heartbeat and darker than normal urine
  • You’re unable to keep down fluids
  • You’ve been vomiting for over 48 hours or you have frequent bouts of vomiting
  • You’ve unintentionally lost a lot of weight

Your GP will discuss your vomiting and any other symptoms with you, as well as examining your stomach and perhaps testing your blood and/or urine. You may also be asked to do a pregnancy test.

If required, your GP will refer you to a consultant for further investigations, diagnosis and treatment.

Treatments for vomiting

Home remedies

The best way to treat vomiting is to stay at home and take it easy. You can also try:

  • Avoiding solid food until you’ve stopped vomiting
  • Replacing lost sugars and salts with fruit juices and salty snacks
  • Taking frequent sips of water — it is important to rehydrate your body even if you have only vomited once; try to stick to drinking clear fluids
  • Using oral rehydration sachets to prevent dehydration

Alternative remedies include drinking ginger tea, ginger ale and ginger beer, and if you can face food, ginger biscuits, as well as foods or drinks containing bergamot or lemongrass oil. As these are alternative remedies, they may interact with any medications you are taking. So make sure you speak to your GP before trying these remedies.

If you have frequent bouts of vomiting eg due to morning sickness, you can try changing your diet to reduce your risk of vomiting. Foods that may reduce your risk include non-greasy foods, plain crackers and foods or drinks containing ginger. Eating smaller but more frequent meals may also help. 

If you have morning sickness, you might also find it helps to nibble on crackers before getting out of bed. Some pregnant women find that a high protein snack before bed also helps reduce nausea and vomiting. Your GP or midwife will be able to advise you about other ways to relieve morning sickness.

Medication for vomiting

For motion sickness, your GP or pharmacist can recommend an over-the-counter medication you can take before travelling.

In some cases, your GP may suggest anti-sickness medication. If needed, your GP will prescribe medication for any underlying conditions linked to your nausea or refer you for treatment. If you're pregnant, always check with your doctor or midwife before you take any medications.

If your vomiting is a side effect of medication, your GP or consultant may prescribe a different medication or change the dosage.

Preventing vomiting

If your vomiting is caused by an underlying health condition, a specific treatment plan will help prevent vomiting. 

Avoiding vomiting triggers can also help. Triggers vary from person to person but include: 

  • Eating too much food, or hot or spicy foods
  • Exercising after eating
  • Drinking too much alcohol
  • Having a migraine
  • Lack of sleep
  • Stress

Following a healthier diet and lifestyle will reduce your risk of vomiting too. Sometimes vomiting is caused by a virus. Although it can be hard to avoid these viruses, you can reduce your risk of becoming infected by practising good hygiene eg regularly washing your hands. 

Frequently asked questions

What does the colour of vomit mean?

The colour of your vomit may indicate the underlying cause of your vomiting. For example, if your vomit is:

Green or yellow you may have a blocked bowel, bile reflux, food poisoning or the flu
Pink, red or dark red you may have a burst blood vessel in your gastrointestinal tract, a stomach ulcer or inflammation in your gut; blood in your vomit is also a sign of certain cancers
White and foamy you may have acid reflux
If you have blood in your vomit, your vomit may also appear to have brown coffee granules in it. Gastroenteritis and morning sickness can both cause your vomit to be clear, green, yellow or orange. If you are concerned about the colour of your vomit, see your GP.

Is it bad to hold in vomit?

Yes, if you feel the need to vomit, you should. Vomiting is usually your stomach’s way of getting rid of harmful substances, such as excessive alcohol, poisons, bacteria or viruses.

Why do I feel better after vomiting?

As vomiting is usually your stomach’s way of expelling harmful substances, once those substances are gone, you will naturally feel better.

Should I sleep after throwing up?

In general, it is best to wait until you feel that you no longer want to be sick. Otherwise, you may vomit again while you are lying down sleeping and you may choke on your vomit. Once you no longer feel as if you want to be sick, try to sleep with your upper body slightly propped up on a pillow, just in case you do vomit again.

How to stop vomiting?

If you are having frequent bouts of vomiting or know that you will likely vomit (eg due to motion sickness), your doctor may prescribe anti-nausea medication. If you are pregnant and vomiting for an extended period of time, your doctor may also give you anti-nausea medication or if your vomiting is severe, an anti-nausea injection.

In general, you can reduce your risk of vomiting by not drinking too much alcohol, practising good hand hygiene to avoid food poisoning and avoiding other triggers (eg very greasy food, sleep deprivation, exercising soon after eating and travelling by sea if you get seasickness).

How to cure hangover nausea and vomiting?

It is important to stay hydrated by drinking lots of water and if you are able, eat foods that will be gentle on your stomach but still replenish lost nutrients (eg a thin vegetable broth).

Why do I feel like vomiting but nothing comes out?

Feeling like you want to be sick (nausea) doesn’t always cause vomiting. This may be because your stomach is empty or because the cause of your nausea is not due to harmful substances in your stomach that your body needs to get rid of. For example, nausea can be caused by pregnancy, lack of sleep and stress.