Air travellers should notify airlines of any medical conditions they may have before flying, the Civil Aviation Authority (CAA) has advised.
According to CAA statistics, 514 health-related emergency calls were made by UK airlines last year, resulting in 58 diversions due to sick passengers.
According to the CAA, letting cabin crew know about any potential medical problems will mean that passengers can avoid causing "huge disruption" for others onboard.
Jason Wakeford, spokesperson for the CAA, says: "It is important to know of any condition that may cause you problems during the flight, well in advance. If you have a condition that can be exacerbated by the conditions inside an aircraft, then you do not want that happening at 30,000 feet where medical protection may be very hard to come by."
The onus is on the passenger to bring a note from their GP and to have an assessment before they travel, rather than on the airline to be ready to handle a whole range of medical conditions in the sky.