Do not fly soon after surgery. The change in atmospheric pressure may impede the healing process. If you must travel, consult your physician to seek advice on making a flight more bearable.
Try not to travel if you have a head cold, flu, or sinus infection. The cabin pressure will make the symptoms feel worse. If you must travel, tote your decongestants or herbal remedies, and coat your nasal area with petroleum jelly to avoid extra tenderness.
Part of remaining healthy is to make sure that you are financially prepared for illness or accidents. Purchase travel insurance before you fly. The insurance offered at the airports is usually much more expensive.
Keep all vital medications with you on board. Ask for your doctor to issue extra prescriptions if the medications are essential to your health. More than once, passengers have left their heart medications behind and it can be difficult to obtain it elsewhere.
When you are traveling at 30,000 feet do you feel more like you are in the desert? The air is very dry (and recycled) when you fly, and alcohol, which has its diuretic effects, can be much more potent. Either compensate with more water, or reduce alcoholic intake. Otherwise, headaches and bloating may become your unwelcome travel partners.
Stretch! Not only will it help keep the blood flowing, but it will alleviate the cramping and pains that come from sitting for an extended period of time. Move around the cabin every once in a while, see if there are pockets of air on the flight that seem fresher than the air around your seating area!
A number of foods served inflight are laden with sugar, or have a `heavy' feeling to them. Because such foods can cause fluctuations in blood sugar and leave you feeling bloated and achy, be wary of them. Sometimes toting your own snacks can make sure you feel at least somewhat the same when you disembark as when you boarded your flight.
Always bring a summary of your medical history with you. If something should happen inflight, having a list available of allergies, medications, contact lense prescriptions, etc., could prove to invaluable.
Load up on the vitamins before you board. Fresh air is a foreign concept on flights, and in such confined quarters you may be susceptible to air-borne infections or diseases. A face mask is not always alarmist, especially if your immune system has been weakened by a recent flu, or by a virus.