Nausea is the feeling of wanting to be sick (vomit). Vomiting is when you are sick, or 'throw up'. The contents of your stomach rise up your food pipe (gullet, or oesophagus) and spill out of your mouth or nose. Nausea and vomiting are controlled by a combination of the vomiting centre in your brain, and areas within your gut.
Nausea and vomiting may be due to many different causes. Common causes include food poisoning, a tummy bug (viral infection), drinking a lot of alcohol, and being pregnant. You should get medical advice if you vomit repeatedly for more than 48 hours or feel unwell or weak. If you vomit blood or have unexplained problems like weight loss or difficulty swallowing, you should see your GP urgently. The most common causes are mentioned below.
Your doctor will want to know
The doctor will want to know how long your feeling sick and being sick (nausea and vomiting) have lasted and whether you have any other symptoms. The doctor will particularly ask about symptoms which may suggest an underlying serious condition. These are known as 'red flags'. The sort of information your doctor will want to know includes the following:
- Did it start suddenly or develop over time? Did anything trigger it? How long has it lasted?
- When do you vomit? Is it worse when you move your head?
- Do you feel feverish?
- Are you coughing up blood or bile?
- Do you feel ill? Do you have a high temperature (fever), weight loss or tummy (abdominal) pains? Do you have headaches?
- How much alcohol do you drink?
- When was your last period? Could you be pregnant?
- Have you started any new medication recently?
This information will help the doctor to work out the cause of your nausea and/or vomiting. Your doctor will examine you. He or she will check your temperature, chest and abdomen. You may be asked to produce a urine sample and have a blood test. You may be asked to do a pregnancy test. Further tests of your stomach and abdomen may be advised. Referral to a specialist is possible.
What can you do if you develop nausea and vomiting?
- Call 111 if being sick (vomiting) is severe and you are weak or have severe tummy (abdominal) pain. If you are so ill that you feel it is a life-threatening emergency, call 999.
- See your doctor urgently (within a few days) if you develop 'red flag' symptoms.
- See your doctor if your vomiting lasts for more than 48 hours and is not improving.
- Avoid a lack of fluid in your body (dehydration): drink little and often to replace any fluid you have lost. Consider using rehydration drinks, such as Dioralyte®.
- If you have motion (travel) sickness and you do not have access to medicines:
- Try breaking the journey to have some fresh air, drink some cold water and, if possible, take a short walk.
- Try to change your seating (for example, move to the front of a car, or to the middle of the deck of a boat.
- Breathe fresh air and avoid strong smells (for example, petrol and diesel fumes).
- Close your eyes (and keep them closed for the whole journey). This reduces 'positional' signals from your eyes to your brain and reduces the confusion.
- Don't try to read.
- Try listening to an audio book with your eyes closed.
- Try to sleep.
- Do not read or watch a film.
- Don't watch moving objects such as waves or other cars. Instead, look ahead, a little above the horizon, at a fixed place.
- If you are the driver, offer to drive, as you are less likely to feel sick if you concentrate on the road ahead.
'Red flag' symptoms that may suggest serious underlying disease
The following features may indicate serious underlying disease:
- Bringing up (vomiting) blood or bile.
- Weight loss.
- Severe tummy (abdominal) pain.
- High temperature (fever), neck stiffness, a rash, reluctance to look at light.
- Increasing weakness/loss of consciousness.
- Continuous or worsening vomiting after 48 hours.
What causes nausea and vomiting?
There are many causes of feeling sick and being sick (nausea and vomiting). The following is a list of some of the most common or important causes. See the links for more information about each condition.
- Gastroenteritis (see also Gastroenteritis in Children).
- Food Poisoning (see also Food Poisoning in Children).
- Pregnancy (see Morning Sickness in Pregnancy).
- Inner ear problems (see Vestibular Neuritis and Labyrinthitis and Ménière's disease.
- Motion (travel) sickness.
- Medications - eg, chemotherapy.
- Urinary tract infections (see Cystitis in Women, Urine Infection in Men, Urine Infection in Children, Urine Infection in Older People and Kidney Infection (Pyelonephritis).
- Eating disorders (eg, bulimia nervosa).
- Stomach problems - for example:
- Gastro-oesophageal reflux disease (GORD). This condition is acid reflux and oesophagitis. It also tends to cause pain at the top of the stomach and (in reflux) a sense of burning or acid behind the breastbone. Reflux can also occur in babies.
- Stomach ulcers. These are seen in severe liver disease and gastric cancer, and usually cause severe pain and intolerance of food.
- Gastroparesis (delayed stomach emptying). This is more common in people with diabetes, people who have had weight-loss surgery and in Parkinson's disease.
- Pyloric stenosis (in babies).
- Metabolic conditions - for example:
- Diabetes, particularly if poorly controlled. Diabetic ketoacidosis (when breakdown products called ketones circulate in the blood) occurs most commonly on patients who are on insulin, and is usually caused by being unwell and not using enough insulin. It can cause persisting, increasing vomiting.
- Addison's disease. This rare condition develops over several months and also causes severe fatigue, weight loss, low blood pressure and other symptoms.
- Hypercalcaemia. A high calcium level is most commonly due to parathyroid gland overactivity, but it can also be caused by certain cancers.
Appendicitis, inflammation of the pancreas (pancreatitis), kidney stones, stomach ulcers and gallstones can all cause severe tummy (abdominal) pain and nausea and vomiting. If severe, ring 111 for urgent advice or 999 to call for an ambulance if you feel it's a life-threatening emergency.
Blockage (obstruction) of the gut - repeated and severe vomiting may be due to a blockage anywhere along the gut (intestine). This could be a twisted loop of bowel, cancerous growth or non-cancerous narrowing. This will usually be associated with severe tummy pain. Because there is a blockage, usually you would be unable to open your bowels. This is an emergency and you need to call an ambulance.
Raised pressure in the brain - meningitis, brain tumours and head injuries can increase pressure in the brain, which can cause nausea and vomiting. Ring 999 to call for an ambulance if you suspect your child has meningitis.
Liver disease - for example, hepatitis A, hepatitis B, liver cirrhosis. There will be other symptoms, including yellowing of the skin and of the whites of the eyes (jaundice) and, usually, pain over the liver.
What is the difference between acute and persistent nausea and vomiting?
Acute nausea and/or vomiting usually mean lasting less than 24-48 hours. They are most commonly due to gastric infection or food poisoning and are self-limiting (ie each stops by itself). This sort of nausea and vomiting does not usually need any intervention unless it is very severe, the vomit is unusual (for example, bloody) or the person affected is a baby or young child and not managing fluids, or if lack of fluid in the body (dehydration) is a problem.
Persistent nausea and vomiting is that which lasts for 48 hours or more. It can have the same causes as acute nausea and vomiting, but simple infections and food poisoning start to look less likely as time goes on, and other possible causes come to the fore. Some are more serious than others, and many cause other symptoms too.
Problems caused by persistent nausea
Persistent nausea, which is that experienced in pregnancy, on a long sea voyage, when taking chemotherapy, or due to a chronic medical condition, can be very distressing. Severe nausea can be exhausting and depressing, and some people think it is worse than vomiting (which can feel like a relief to people with persistent nausea).
Problems caused by persistent vomiting
- Repeated vomiting can cause dehydration, particularly in babies and small children.
- Persistent vomiting leads to loss of water and salts from the body, including sodium, potassium and chloride. Altering the balance of the body's salts can lead to complications, including irregularities of the heart rhythm. It can be very difficult to replace lost fluids and salts whilst vomiting continues.
- Tooth enamel damage is common in people with bulimia nervosa who induce vomiting on a regular basis as part of their illness. The acid from the stomach erodes and damages teeth, and digestive enzymes damage gums, leading to dental complications.
- Tears of the oesophageal lining (Mallory-Weiss tears) can cause bleeding, and you may see blood in the vomit. Recurrent vomiting can also lead the stomach and gullet to become inflamed (gastritis and oesophagitis).
- Vomiting whilst unconscious (for instance, after excess alcohol) can be very dangerous, as it can lead to stomach contents getting into your windpipe, and therefore into your lungs, where it can obstruct breathing or lead to severe lung inflammation.
Further reading and references
Diarrhoea and vomiting in children under 5; NICE Clinical Guideline (April 2009)
Guidelines for the management of norovirus outbreaks in acute and community health and social care settings; Public Health England (March 2012)
Spinks A, Wasiak J; Scopolamine (hyoscine) for preventing and treating motion sickness. Cochrane Database Syst Rev. 2011 Jun 15(6):CD002851.
Nausea/vomiting in pregnancy; NICE CKS, February 2020 (UK access only)
Gastroenteritis; NICE CKS, March 2019 (UK access only)
Palliative care - nausea and vomiting; NICE CKS, October 2016 (UK access only)
Boelig RC et al;. Interventions for treating hyperemesis gravidarum. Cochrane Database Syst Rev. 2016(5):CD010607. Published 2016 May 11. doi:10.1002/14651858.CD010607.pub2