Going on holiday is great – but getting there is no fun if you suffer from travel sickness.

Whether you call it travel sickness, car sickness, sea sickness or air sickness, it’s all motion sickness really, and it can cause unpleasant symptoms including dizziness, nausea and vomiting, headaches and fatigue.

But why do you get it, and what can you do about it?

Mixed messages

Motion sickness occurs because the brain gets conflicting messages from travelling – the muscles tell it the body’s stationary, while the fluid in the ears detects motion.

Neuroscientist Dr Dean Burnett, author of The Idiot Brain, says: "The reason we experience motion sickness is that the fundamental processes in our brains, the ones which integrate all our sensory information into one coherent view of the world, haven't evolved the ability to recognise motion caused by vehicles yet.”

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Dr Burnett, who works at Cardiff University, says that when we walk or run our muscles are working, balance sensors in the ears detect the forward motion or acceleration, distinct patterns of movement are detected by the eyes, and there’s a regular impact on the legs.

But when in a vehicle we're not consciously moving ourselves, so the muscles and body are stationary as far as the brain’s concerned. We're also typically in an enclosed environment, especially in a plane or ship, so the eyes can't see the world going by and the visual system thinks we're stationary too.

“However, the balance sensors in our ears respond to the laws of physics, and they sense all the acceleration and movement quite acutely, so they say we’re moving,” explains Dr Burnett. “This means the brain is getting mixed signals from the senses.”

Travel poison

The brain doesn’t like these conflicting signals, and as its more fundamental areas don't understand the concept of vehicles, it draws one simple conclusion: it’s being poisoned.

“As far as it knows, there's only one thing that can lead to this mismatch in the senses, and that's when we've been poisoned by something that scrambles our neurological systems,” says Dr Burnett. “And the quickest way to get rid of poison is to throw up.”

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Easy rider

Travel sickness doesn’t affect everyone because some have a more efficient link between the higher rational brain regions and the fundamental ones, so the confusion is avoided or overridden.

Children get motion sickness more often as their brains and the connections in them are still being formed, so they’re easier to confuse.

“But some people just seem unlucky to have brains which don't deal well with the mixed signals,” says Dr Burnett.

How to stop travel sickness

- Try motion sickness drugs, which work by suppressing nerve signals from the part of the brain where the balance sensors are found, thus reducing the mismatch in sensory information.
- Sit in the front of a car, in the middle of a boat or over the wing of a plane, where motion isn’t as obvious.
- Keep your head from moving by using a pillow or headrest if you can.
- Don’t watch a film or read.
- Stare above the horizon at a fixed place.
- Don’t have a big meal or alcohol before and during travel.
- Get some fresh air, and don’t get too hot.
- Try acupressure wristbands, which claim to disrupt the nausea and vomiting signalling process between the brain and the stomach by putting pressure on points on the wrists.
- Break up the journey if possible.

How do you combat travel sickness? Tell us in the Comments box below