Sensors in our inner ear help to keep us balanced. These tiny, liquid-filled, semi-circular tubes act like spirit levels and are positioned in three planes, detecting movement and reporting it to the brain whichever way we move. The brain also receives messages from the eyes. Travel sickness is the result of conflicting messages from the eyes and the inner ear. If you're a passenger in a car, the sensors in your ear tell your brain you are moving while your eyes are seeing the relatively stationary inside of the vehicle. The driver won't feel sick because he is looking at the moving road - the messages to the brain are the same.

Be prepared for happier holidays

• Eat a light meal at least 3 hours beforehand. Avoid fatty or dairy foods.
• If you are in a car or coach, look outside at objects far away. Don't read or play video games.
• Ask the driver to take bends slowly, and not to 'accelerate-break' when approaching a bend.
• Avoid too many head movements; press your head into the headrest.
• In a ship, try to stay on deck and look at the far horizon. If you have to go inside, go to a low deck and try to be as near the middle of the ship as possible, the position of least movement. In a plane, try to get a seat near the wing.
• Make sure there is plenty of fresh air, and keep away from smokers.
• Ginger often helps. Chew some crystallized ginger or nibble ginger biscuits.
• Acupressure bands worn on the wrists are popular, though there is no good evidence that they work. But a scientific study found that pressing on the acupressure point does work. The acupressure point is in the middle of the inner wrist, about 3cm above then wrist skin crease.
• Buy motion sickness tablets from the chemist. There are two main types. Joy-rides and Kwells contain hyoscine. These work within about half an hour, but you may get a dry mouth. Other tablets, such as Sea-legs, contain antihistamine and act more slowly. Both types can make you drowsy.