As the weather gets warmer，there are few things that are better to do than travel．But traveling might not be that fun for everyone，especially for those who have motion sickness（晕动症）．
Motion sickness is also called travel sickness．It is a common experience for many people．Depending on how you travel，it can be called carsickness or seasickness．People with motion sickness feel very uncomfortable while they are in motion．They feel sick and dizzy，like the room around them won't stop spinning．
It is generally believed that motion sickness happens when your senses become confused （困惑的）with each other，Scientific American reported．
We use different parts of our body to sense movement．Our eyes tell us if we are moving．The inner ears （内耳） contain a special liquid that helps us sense our direction and balance．Our muscles react to movement．
When you move around，these body parts work well together．But when you are in a car or an airplane，they get confused．Your inner ear signals that you're moving．This mismatch gives us motion sickness．
But some people are less sensitive to motion sickness．This may be because they have certain genes （基因） that prevent mismatching senses，Bethann Hromatka，told the Atlantic．
Although there are many ways to deal with motion sickness，scientists believe that the key is to simply try to adapt to it．For example，some astronauts do special exercises that give them mild motion sickness．After a week or two，the astronauts become used to it and don't feel uncomfortable anymore，a NASA flight doctor，told the BBC．
