Nausea and vomiting

What is nausea?

Nausea is the feeling you get when you are about to vomit. People often describe feeling nauseous as 'feeling sick', as if they are going to be sick (vomit).

Nausea is a very common symptom, and almost everyone has experienced it at least once in their life.

Sometimes, people feel nauseous but don't actually vomit. Often, the feeling of nausea gets better after vomiting, although sometimes it can remain despite vomiting, which can be very unpleasant.

What causes nausea and vomiting?

Nausea and vomiting are common symptoms. 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).

  • This is a very common cause of vomiting and diarrhoea.

• Food poisoning (see also Food poisoning in children).

• Alcohol.

• Cannabis use.

• Pregnancy (see Nausea and vomiting in pregnancy).

• Migraine.

• Premenstrual syndrome. Nausea before a period can be normal for some people.

• Inner ear problems (see Vestibular neuritis and labyrinthitis and Ménière's disease.

• Motion (travel) sickness.

• Medications - eg, cancer treatments such as 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 is caused by acid coming up from the stomach and into the oesophagus (food pipe). It causes 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. Vomiting blood can occur if the ulcers bleed.

  • Gastroparesis (delayed stomach emptying). It can cause vomiting after eating. 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.

Other causes

Appendicitis, inflammation of the pancreas (pancreatitis), kidney stones, stomach ulcers and gallstones can all cause severe stomach 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 abdominal 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.

Kidney problems - for example, chronic kidney disease, which typically causes nausea when severe, and kidney stones (which may also cause pain).

You should get medical advice if you vomit repeatedly for more than 48 hours, feel weak, vomit blood or have problems with weight loss or difficulty swallowing. . If you vomit a large amount of blood then it may be more appropriate for you to go to Accident and Emergency.

What is the difference between acute and persistent nausea and vomiting?

Acute nausea and/or vomiting usually means lasting less than 24-48 hours. It is most commonly due to gastric infection or food poisoning and is 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.

Your doctor will want to know

The doctor will want to know how long your feeling nauseous 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 to do to help nausea and vomiting

• Avoid a lack of fluid in your body and signs of dehydration: drink little and often to replace any fluid you have lost. Drinking small amounts regularly is easier to keep down. Consider using rehydration drinks, such as Dioralyte®.

• If eating food makes you feel nauseated then it is fine if you want to try avoiding solid food, but you may find that eating small amounts of plain food makes you feel a little better. Avoid strong smelling foods, which can make nausea worse.

• 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.

Seek medical care urgently if you develop these.

Vomiting and diarrhoea in children are usually caused by gastroenteritis, but vomiting without diarrhoea may suggest a different cause, including other types of infection. If a child has persistent vomiting but no other symptoms, see a doctor.

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.