What should you know about motion nausea?

It can happen in a car, boat, aircraft, amusement ride or virtual-reality setting. Symptoms may include queasiness, cold sweating, dizziness, headache, extra saliva, tiredness and vomiting. They often improve after the movement stops, although some people feel washed out for a while afterwards.

Your inner ear detects acceleration and balance, while your eyes report what you can see. For example, reading in a moving car makes your eyes focus on a still page while your balance system senses turns and speed. The brain has difficulty combining these messages, which can trigger nausea and other autonomic symptoms.

Motion nausea is different from nausea caused by an infection, food poisoning, medication or another illness. If sickness occurs when you are not moving, or continues well after a journey, consider other explanations such as acid reflux, gastritis, gastroenteritis or hypoglycaemia with a clinician.

Choose a position with the least movement: sit in the front passenger seat of a car, face forward, look at the horizon, or stay near the centre of a boat. Avoid reading, watching a screen and turning your head repeatedly. Fresh air and slow, regular breathing may make the journey easier.

Before travelling, eat a light meal and drink water. Avoid heavy, greasy or spicy food and alcohol if these worsen your symptoms. If you are prone to motion nausea, ask a pharmacist or doctor about a suitable preventive medicine before the journey; some options cause drowsiness and may not suit everyone. Do not drive after taking a medicine that makes you sleepy.

Seek urgent medical help for severe or persistent vomiting, fainting, confusion, severe headache, chest pain, trouble breathing, weakness on one side, or new difficulty speaking or walking. Get prompt advice if you cannot keep fluids down, pass very little urine, or have signs of dehydration such as marked dizziness and a dry mouth.

Arrange a medical assessment if nausea starts without movement, repeatedly returns, lasts after travel has ended, or comes with fever, severe abdominal pain, yellowing of the skin or eyes, or blood in vomit. These features can point to problems such as gallstones, hepatitis A, heat exhaustion or another condition rather than motion nausea.

Ask which preventive treatment fits your age, health conditions and other medicines, and how long before travel it should be taken. Mention pregnancy, glaucoma, prostate or bladder problems, balance disorders, allergies and any previous reaction to travel-sickness medicine. Describe when symptoms begin, how long they last, whether vomiting occurs and whether they happen away from moving vehicles.