In each inner ear there are small canals filled with fluid which moves when your head moves. This movement stimulates nerve endings which send messages to your brain about your head position. The system works closely with your eye muscles, allowing you to focus on an object even when you are moving.

This finely tuned system helps keep us upright and balanced. If there is a problem, you may feel dizzy, nauseous, have blurred vision, flickering eyes or feel unstable when walking. You might also get neck pain as the muscles are working too hard to keep you balanced. These symptoms may last from a few seconds to many months.