Dizziness, vertigo, and motion sickness all relate to the sense of balance and equilibrium. Researchers in space and aeronautical medicine call this sense spatial orientation, because it tells the brain where the body is "in space:" what direction it is pointing, what direction it is moving, and if it is turning or standing still.
Your sense of balance is maintained by a complex interaction of the following parts of the nervous system:
The inner ears (also called the labyrinth), which monitor the directions of motion, such as turning, or forward-backward, side-to-side, and up-and-down motions.
The eyes, which monitor where the body is in space (i.e. upside down, rightside up, etc.) and also directions of motion.
The skin pressure receptors such as in the joints and spine, which tell what part of the body is down and touching the ground.
The muscle and joint sensory receptors, which tell what parts of the body are moving.
The central nervous system (the brain and spinal cord), which processes all the bits of information from the four other systems to make some coordinated sense out of it all.
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.
Content Courtesy : www.entnet.org
^{Note : Information herein is provided for informational purposes only and is not a substitute for professional medical advice. You should not use this information for diagnosing or treating a medical or health condition. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider. Please consult your healthcare provider before beginning any course of supplementation or treatment.}