Carsick means feeling nauseated or queasy from riding in a moving vehicle. When you're carsick, your stomach feels upset and you might feel dizzy, sweaty, or like you might vomit. It happens because your inner ear (which helps you balance) senses the car's movement, but your eyes might be looking at something stationary, like a book or a phone screen. Your brain gets confused by these mixed signals and responds by making you feel sick.

Some people get carsick more easily than others. Long, winding roads with lots of turns can make it worse, especially if you're reading or looking down. Many people find that looking out the window at the horizon or sitting in the front seat helps, because then their eyes see the movement their body is feeling. Getting fresh air by opening a window can also help.

The same kind of motion sickness can happen on boats (seasick) or airplanes (airsick). If you've ever had to stop on a road trip because someone felt carsick, you know how uncomfortable it can be.