Travelling by plane
The oxygen supply and pressure in the aircraft is equivalent to that found at an altitude of approx. 2,400 metres above sea level, which is about the same as on the top of the Gotthard Pass. That means that the air pressure, humidity and oxygen in the cabin are reduced. During the ascent, the aircraft increases altitude at a rate of some 150 metres a minute; during the descent, altitude decreases at a rate of approx. 90 metres a minute. While the air-conditioning systems regulate the ventilation and temperature in the cabin, they cannot produce natural humidity. These changed conditions lead to vascular dilation, an increase in the heart rate by 5-10 %, a slight increase in the breathing rate and a marginal increase in the upper blood pressure value. Moreover, a redistribution of the body’s blood circulation occurs: the heart and brain are supplied with more blood, the skin, kidneys and gastro-intestinal system with considerably less.
Drink plenty of fluids, preferably still water. During long flights, loosen up your leg muscles from time to time, rotate your ankles and flex your feet while sitting down
The reduced oxygen saturation of the blood goes unnoticed by a healthy person and is harmless. The changes in air pressure are also scarcely perceivable. This only results in earache if you have a cold and the pressure is not equalised. In this case, you should try chewing or yawning during the ascent and descent phases of the flight; nose drops, sprays or ointments can also reduce or prevent earache. The dry air in the cabin leads to the mucous membranes drying out. Sitting down for periods of several hours reduces the circulation in the legs. Crossing several time zones disrupts your body clock (jet lag).
Simple preventative measures
Drink plenty of fluids, preferably still water. During long flights, loosen up your leg muscles from time to time, rotate your ankles and flex your feet while sitting down. Avoid putting items of luggage on the floor in front of you (restricts legroom). Avoid drinking alcoholic beverages. Sedatives or sleeping pills should be taken with caution.
Ill people are restricted in their fitness to fly. In particular, heart or lung diseases, anaemia, existing circulatory problems and vein disorders can have unpleasant consequences. If medicaments need to be taken regularly (insulin or other antidiabetica, hormone pills, blood-thinning tablets, etc.) and you are crossing several time zones, be sure to take them at the right time. Ask your GP about the possible risks of a trip by plane and when you should take your medicaments!