There has been considerable literature written in the past few years about this subject.
In the past, those of us who travelled simply had to live with it all, just hoping for the best. Today we can take steps to at least marginalize some of the effects.
Many will report that they often find they get sick after flights, long or short, blaming the quality of the air in-flight on the aircraft manufacturers.
The reality is that today’s aircraft offer better air quality than will be experienced in many homes and offices.
Where the challenge exists, however, is in helping our bodies manage in-flight temperatures and bacteria that are brought or left onboard by fellow passengers.
In previous columns I have written about the state of the seat trays and washrooms. While clean, they may be decidedly not bacteria-free.
Take a quality disinfectant spray onboard in an acceptable 100 ml bottle and use it to immediately clean your tray and arm rests. Likewise, wipe the taps and other surfaces in washroom areas before you use them.
Dress in layers to accommodate any temperature variances the airline may throw at you.
While they do try to create average temperature controls to suit the health requirements of most of us who travel, I have been on flights where I have perspired and others where I have approached near-shiver conditions.
With a layered clothing strategy you can add or subtract garments as required. It is also wise to wear lose fitting clothing on long journeys.
Not only will this contribute to a more comfortable trip, but tight clothing of any kind can impede proper blood flow which can contribute to the condition in the other part of your question, DVT, or deep vein thrombosis.
While not exclusive to air travel, DVT is known to occur most frequently on long flights.
It is a condition that happens as a result of blood clots that form in veins. Experts say when this happens it raises the potential for pulmonary embolisms. It has been referred to as ‘hospitality class syndrome’ because of the fact seats are not only smaller in these sections, but passengers tend to stay in them too long, perhaps not wanting to disturb others in the row, or just from a lack of understanding about how important it is to find ways to increase circulation by exercise of any kind.
We can take actions to alleviate some of the conditions present during flights.
On these long haul flights it is especially important to get up often to walk around and stretch. There are also a number of in-seat exercises that can be undertaken. A number of airlines actually offer suggestions of some of these on their websites. The website http://www.videojug.com/film/how-to-do-an-in-flight-fitness-workout has a video demonstration of some of them which are easy to do while flying.
Dehydration is another contributor to DVT. Drinking lots of the right liquids will not only help prevent DVT but will help lessen the impact of jet lag as well. Alcoholic beverages are definitely not the right choice if you are serious about doing the right thing for your travel health; nor are caffeinated beverages.
Water is the best for you, and while flight attendants do try to walk up and down the aisles as frequently as possible with water, their other duties prevent them from coming by often enough to keep most people hydrated.
The bloating effect of carbonated beverages can also be a problem for many. I buy a large bottle of water, post security, for almost every flight we take, regardless of duration.
Watch what you eat before boarding as well. Greasy foods are best to avoid in the hours beforehand.
Your choice of shoes is important. With the change in cabin pressure feet will often swell during flights. Wear comfortable shoes. Slip on style footwear can be a great help, and it is worth carrying an extra pair of socks if the temperature in the aircraft gets cooler during your flight.
There are a variety of compression socks available on the market and, if recommended by your physician, can actually be used as a tax deduction. http://journeystravelgear.com/Results.cfm?keywords=travel%20sox A few years ago there were only one or two manufacturers who offered these socks designed specifically to help increase circulation.
Today they are easy to find at many retail outlets that offer a wide variety of footwear and socks.
There are also now a number of homeopathic tablets which help control the impact of jet lag. One of them is a product called No Jet Lag, http://www.nojetlag.com/. On the site you can find a list of links to independent publications who have reviewed the product. You can buy it at http://journeystravelgear.com/Results.cfm?keywords=no%20jet%20lag
While many of the effects of long distance travel are physical, there is also an important mental aspect as well.
In the confined spaces that offer few options for normal activity it is hard to keep the mind occupied for such long periods of time. Time does indeed fly faster when you are busy. Take work projects with you and do them for a couple of hours at a stretch. Find the best books you can that you are certain will encapsulate you. Bring your favourite music along, and even though movies are a standard offering on long distance flights if you have a portable DVD player, take it with you along with the movies you have been waiting to watch for some time.
There are few people who are not impacted negatively by long distance flights in some way. I hope these suggestions will make this expedition, and others you may take, more satisfying.
If you have travel questions or coments email me at firstname.lastname@example.org. I will answer your question and it will appear later right here on Tripatlas.
See other travel tips on my website at www.journeystravelgear.com