Persistent nausea: causes, red flags and what to do

Nausea is the unpleasant feeling that you might be sick. It can come with or without actual vomiting, and it can be accompanied by dizziness, sweating or loss of appetite. There is no fixed definition of persistent nausea in the NHS advice, but the practical message is that nausea that lasts more than a few days, or that keeps returning, should be checked rather than endured.

Nausea is a symptom, not a diagnosis. The sensation can be generated by the stomach and gut, by the balance system in the inner ear, by the brain, or by hormones and medicines acting on the brain's vomiting centre. That is why the pattern of other symptoms matters so much when a GP works out the cause.

The NHS page on feeling sick pairs symptoms with likely causes. Diarrhoea or vomiting suggests norovirus or food poisoning; a headache and high temperature suggest an infection such as flu; heartburn or bloating after eating suggests acid reflux; headache with sensitivity to light or sound suggests migraine; and dizziness suggests labyrinthitis or vertigo. Other reasons include pregnancy (morning sickness), motion sickness, anxiety, alcohol, medicines and recent surgery.

The NHS dizziness page adds that nausea together with a spinning sensation, sometimes after a cold or flu, can point to labyrinthitis, and that new symptoms after starting a prescription medicine may be a side effect. If nausea began soon after a new tablet, check the leaflet and speak to a pharmacist or GP rather than stopping prescribed medicine on your own.

• Stomach and gut: gastroenteritis, reflux, medicines, food intolerance.

• Head and ears: migraine, labyrinthitis, vertigo, motion sickness.

• Whole body: infections, pregnancy, anxiety, alcohol.

• Treatments: some medicines and recent surgery.

The NHS suggests getting plenty of fresh air, distracting yourself with music or a film, taking regular sips of a cold drink, drinking ginger or peppermint tea, eating foods containing ginger such as ginger biscuits, and eating smaller, more frequent meals.

It also lists things to avoid: strong-smelling food, hot, fried or greasy food, eating too quickly, large drinks with meals, lying down soon after eating and clothes that are tight around the waist or tummy. These are simple measures, and they do not replace finding the cause if the nausea persists.

See a GP if you feel sick and do not feel better in a few days, or if it keeps coming back. The GP can look for the cause and suggest treatments, and may prescribe anti-sickness medicine if needed. The NHS says to call 111 for advice if you cannot see a GP.

When there is vomiting too, the NHS advice on diarrhoea and vomiting says to call 111 if you or your child keep being sick and cannot keep fluid down, or have vomiting for more than 2 days. It says to call 999 or go to A&E if you vomit blood or have vomit that looks like ground coffee, have green vomit as an adult, have a stiff neck and pain when looking at bright lights, a sudden severe headache, a sudden severe tummy ache, or are confused or not responding as usual.

Call 999 if sudden nausea comes with chest pain that feels tight or heavy, pain that spreads to your arms, back, neck or jaw, or shortness of breath, as this could be a heart attack.

A GP will usually ask when the nausea started, whether it is linked to meals, movement, particular smells or medicines, whether you are vomiting or losing weight, and what else you have noticed. Possibilities include pregnancy in someone who could be pregnant, a medicine side effect, an inner ear cause, or a digestive cause. Examination and simple tests may follow, and a referral if a specific cause needs further investigation.

Treatment depends on the cause. Where the cause is a medicine, a different drug or timing may be possible. Where it is an inner ear problem, the NHS says vestibular rehabilitation exercises can help with dizziness, nausea and anxiety. Short-term anti-sickness tablets may be prescribed, though the NHS cautions that for labyrinthitis they should not be taken for longer than 3 days as they can slow recovery.

Most people are assessed in primary care through the NHS. Private consultations are available for those who prefer faster access to a specialist, but the first step is usually the same: a thorough history and review of medicines. Keeping a simple diary of when nausea occurs, what you ate and what you took can speed things up.

Persistent nausea can affect eating, work and mood. Eating small regular meals, staying hydrated and asking a pharmacist or GP about any medicines you take are sensible steps while the cause is being sorted out.