The causes of motion sickness are: i. Individual differences. When the incoming balance stimulus is excessively strong. Such as when braking sharply or spinning violently, it is normal for people to feel dizzy even when the balance system is safe and normal. Some people have poor tolerance and react strongly to slight balance stimuli. Second, dizziness is likely to occur with poor sleep quality and excessive fatigue. Third, too much hunger and too much satiety also tend to produce motion sickness. Fourth, when suffering from certain ear diseases, also prone to motion sickness. Fifth, the compartment is closed more tightly, so that the air does not circulate, or stimulated by some odors, will also lead to motion sickness.