Talk about a “moving experience!” No matter how fast or far you travel, motion sickness is one thing you can’t always run away from. With symptoms that range from slight nausea to severe vomiting, it can hit when you’re in a moving car, airplane, train, bus or boat. So what causes all the confusion and mayhem? Well, to put it simply, it’s all in your mind.

Deep inside your skull, within your inner ear, is a group of three hair-lined, liquid-filled organs of balance called semicircular canals. The canals contain fluid and have tiny hairs at their base. Any time your body moves, the fluid shifts along with it and presses against the little hairs. In a normal situation, an area of your brain called the pons keeps track of your movements by receiving motion signals from the canals. But when you’re in a violently rocking boat, car or plane, all that jiggling and swaying can send fluid in the semicircular canals sloshing back and forward like water in a bucket. As a result, your motion-sensing cells flood the pons with so many signals that they actually spill over and trigger the vomiting center in a nearby area of the brain. Then you really start losing your senses: Your stomach gets orders to become upset even when nothing’s really wrong, but you (ulp!) upchuck anyway.

So how do you fight motion sickness? The best thing to do is take some preventive measures–they’ll go a long, long way when you’re away on vacation. For one thing, avoid reading books while on the move. Since motion sickness involves a disruption of balance in the inner ear, focusing on moving pages can make matters worse. Keeping yourself distracted can also help. Much of motion sickness is only in your mind, so playing a mental or verbal game with others will make you think less about feeling sick. Finally, take medicine like Dramamine if you know you might get sick on a long trip. It’s no bitter pill to swallow when you consider the icky alternatives.