The symptoms of motion sickness and dizziness appear when the central nervous system receives conflicting messages from the other four systems. For example, suppose you are riding through a storm, and your airplane is being tossed about by air turbulence. But your eyes do not detect all this motion because all you see is the inside of the airplane. Then your brain receives messages that do not match with each other. You might become “air sick.” Or suppose you are sitting in the back seat of a moving car reading a book. Your inner ears and skin receptors will detect the motion of your travel, but your eyes see only the pages of your book. You could become “car sick.” Or, to use a true medical condition as an example, suppose you suffer inner ear damage on only one side from a head injury or an infection. The damaged inner ear does not send the same signals as the healthy ear. This gives conflicting signals to the brain about the sensation of rotation, and you could suffer a sense of spinning, vertigo, and nausea.