When flying on commercial airlines, airline passengers can develop some medical problems which tend to be minor.  However, some symptoms may develop into more serious medical conditions, such as deep vein thrombosis, which can quickly become life threatening.

The fear of flying is called Aviophobia.  There are millions of vacationers and business people who travel on commercial air flights as well as potential flyers worldwide that suffer from it, to a greater or lesser extent.  Even though air travel is about thirty times safer than traveling by car, you very rarely hear about people that have a fear of driving.