According to the passenger's medical condition can be very important to consult your doctor if you have had a recent surgery, especially ocular, abdominal or lung. If you travel with your legs in plaster, if she has suffered stroke or circulatory problems.
As for pregnant women, the airlines recommend not make air travel when the period of gestation over 36 weeks.
Turn requires extreme caution if you have lung disease or respiratory failure, if you have chronic sinusitis, middle ear infections or glue ear or respiratory infections or allergies.
On trips lasting more than three hours, airlines often recommend certain patterns of food and beverages as well as some physical exercise during the flight to help increase the welfare of passengers and reduce the inconvenience of prolonged immobility. Walking the aisles of the plane is usually a good exercise to avoid a possible thrombosis or other complications.