Why Do We Get Motion Sickness? The Sensory Conflict Explained

Oct 15, 2026 · 4 min read · Sourced and fact-checked

The short answer: Motion sickness is triggered when the brain gets conflicting information from the eyes, inner ear and body about movement. A 2019 review says almost everybody has had it, and looking at the horizon can help.

Reading in a car or being on a boat can leave you queasy within minutes. A 2019 review in the journal Drugs in Context explains what is going on.

The brain gets mixed signals

The review says the key ingredient for motion sickness is that the brain receives conflicting information from different sensors about real body movement or a virtual environment. The main sensors are the eyes, the vestibular apparatus in the inner ear, and proprioceptive receptors that sense body position. The brain compares this information with a pattern of expected associations it has stored from normal experience. When the signals do not match, motion sickness can develop.

Real motion is not required. The review notes people can feel symptoms while watching a large moving field or taking part in virtual reality rides, even though they are not physically moving.

What it feels like

Typical symptoms include malaise, nausea, yawning, sighing, more saliva, burping, headache, blurred vision, dizziness, drowsiness, difficulty concentrating, and sometimes vomiting.

How common it is

The review says almost everyone has experienced it at least once. It reports that up to 25 percent of passengers on a large ship develop it within 2 to 3 days of a voyage, and up to 80 percent of astronauts are affected in their first 3 days in space. Less than 1 percent of travellers in pressurised commercial aircraft have it.

Who is more likely to get it

Susceptibility varies a lot. The review says females are more susceptible than males of the same age, children aged 6 to 12 are most susceptible with a peak at 9 to 10 years, and it is rare under age 2 and rarely occurs after age 50. It can run in families, with heritability estimates in the range of 55 to 70 percent.

What helps

According to the review, most cases can be prevented with simple changes in behaviour and surroundings. Reducing visual conflict can delay or weaken symptoms. The review advises avoiding reading or watching a screen in a moving vehicle, sitting in the front seat rather than the back, and focusing the eyes on a fixed spot such as the horizon or looking in the direction of travel. It adds that actively steering a vehicle may help. For more severe cases, some medicines, including anticholinergics and antihistamines, are effective, and work best combined with these changes.

A note

Persistent or severe symptoms should be checked by a doctor. Ask a doctor or pharmacist before using any medicine. This is general information, not medical advice.

Sources

Motion sickness: an overview, Leung and Hon, Drugs in Context, December 13, 2019: https://pmc.ncbi.nlm.nih.gov/articles/PMC7048153/

Facts checked: October 15, 2026.