The aircraft cabin environment can be rather hostile and many travellers complain of different discomforts. Those with pre-existing medical problems may be adversely affected. Travellers should therefore take precautions whenever necessary.
General health problems
Cough. Allergens, dry air, fumes and ozone in the cabin air may cause many passengers to cough more during the flight. Breathing through a handkerchief may help.
Dehydration. Cabin air conditioners remove most moisture from the cabin air by 3 hours into the flight, reducing humidity to an uncomfortable 10% to 20%. This dries out the mouth, throat, eyes and skin. Sucking on hard candies can relieve the dry feeling in the throat. Eye drops help those who must wear contact lens. Skin moisturizers will make skin feel more comfortable.
Nausea and vomiting. Low atmospheric pressure expands air in the gut by about 20% – 30%. Eating smaller portions before and during flights and avoiding carbonated beverages help minimize problems. Motion sickness may cause vomiting.
Headaches. Lots of factors, like tiredness, insufficient oxygen, odours, can increase the risk of migraine and other kinds of headaches. Headache remedies are most effective if taken as soon as pain begins. Breathing through a wet towel may help travellers avoid inhaling fumes.
Fainting. Lightheadedness is the commonest cause of in-flight medical problems. Hyperventilation is a common symptom. Fainting is generally a harmless condition and is self-limiting. Victims generally respond to reassurance and to lying down with their heads lower than the body. But in the flight, fainting may be difficult to distinguish from other conditions like heart attack. Whenever in doubt, oxygen should be given.
Motion sickness. Few people feel motion sickness on jetliners, but such illness is common on small aircraft. Symptoms can be minimized if one fasts for 3 hours before flight, eats three small meals in the 24 hours before flight, and takes mostly carbohydrates.
Earache. Ear pain is especially common in children. Commercial airlines pressurize air cabin to the equivalent of about 2000 metres altitude. During taking off, air within middle ear expands and moves out through the Eustachian tubes to the nose. This generally runs smoothly. Problems arise during descent when air needs to travel back to Eustachian tube to equalize the pressure. At this moment, the Eustachian tube acts like a soft rubber tube, making it difficult to suck air back into the tube. This is what causes pain in the ears of young children. Nursing children with a bottle during descent helps the pain, as sucking and swallowing motions tend to open the Eustachian tube.
Leg swelling. Prolonged sitting in cramped quarters causes pooling of blood in deep veins of lower limbs, resulting in leg swelling. In addition, blood clots may form inside the veins. If the clots travel to the lung, they can cause a serious lung problem. The table below shows the risks factors of and ways to minimize blood pooling in the legs.
Risk factors of blood pooling: