Economy Class Syndrome has been all over the papers and TV headlines for the past several years, with little insight into the problem other than press releases from major airlines, which deny for fear of too many lawsuits, should they be discussed in any detail. We’re told it’s just something that happens to people who are immobile for long periods of time in the economy class section of the plane.
Let’s focus on what economy class syndrome is and what it isn’t. First of all, economy class syndrome is a misnomer because it also occurs in first class and among flight attendants and even pilots. Refers to deep vein thrombosis, or deep vein thrombosis, where blood pools in the deep veins of the legs and then clots. Sometimes, these clots can break off and travel to the lungs or heart, causing a pulmonary embolism or myocardial infarction, also known as a heart attack. Risk factors include inherited clotting factor abnormalities, smoking (nicotine promotes blood clotting), cancer, dehydration, and prolonged immobility.
Blood travels quickly through the arteries, which actively pump blood to all parts of the body. On the other hand, veins are passive and blood flow relies on a one-way valve system. When muscles flex or move the arms or legs, it causes the muscles to put pressure on the veins, which causes blood to return to the heart. If there is prolonged immobility, the blood can clot. These clots, if they are in the deep veins of the lower leg (behind the calf), usually dissolve on their own, but sometimes they break free and can then travel to the lungs and cut off the blood supply there. This is a pulmonary embolism and is often fatal without immediate medical treatment with ‘clot lysis’ (thrombolytic) medication.
The advice given by airlines and most general practitioners is to wiggle your toes from time to time and do other exercises in the seat to keep the blood flowing. Getting up to walk around the cabin every hour or so is also recommended. Drink plenty of fluids and avoid alcohol or caffeinated beverages, as they have a diuretic effect, which increases dehydration. Blood becomes more viscous when dehydrated.
Now, we continue to study why people in business class and flight attendants, who are not in cramped conditions and immobile (in the latter case), develop deep vein thrombosis (DVT), the so-called “economy class syndrome”.
Some articles appeared on the web several years ago, written by a few doctors and pilots, stating that the cause is due to rapid decompression and decompression, especially the rapid decompression that occurred on takeoff. Most airlines pressurize their cabin to be the equivalent of 8,000 feet above sea level because it is not possible to keep an aircraft pressurized to sea level at the high altitudes at which you fly. The fuselage, or fuselage, is not strong enough.
I know you’re thinking, “8,000 feet? That’s like living in the mountains!”. you are right. The amount of oxygen_and_ the pressure is equivalent to living in the mountains at an altitude as high as 8,000 feet. The oxygen content is much lower than on Earth, although most people in good health can tolerate it. It may be wise for people with heart conditions to avoid flying altogether or to use supplemental oxygen during flight.
Low oxygen, dry air, immobility, and low air pressure all contribute to the risk of DVT. In fact, there was a study done where some patients sat in a crowded theater for 8 hours. Tests were done to look for blood clots. nothing was found. However, on an airplane trip, it’s quite another matter. About 1 in 10 passengers form clots, but almost all of these dissolve on their own without further complications. This only adds fuel to the fire as there is just something about being on a plane that causes clots, or causes pre-existing clots to dislodge and travel to the lungs or heart.
With all factors analyzed, the only thing that stands out is the low air pressure and sudden decompression and recompression. The airlines don’t want you to know this, because I’m sure they do and admitting any wrongdoing would mean endless lawsuits or class action against them.
The rapid decompression of flight is a bit like a diver emerging from the water. Divers can suffer from thrombosis if they surface too quickly or fail to undergo proper decompression soon after surfacing. The same concept applies to flying. It can certainly lead to blood clots and usually these clots do not disintegrate until the pressure is re-pressured upon landing and disembarking from the aircraft.
In conclusion, it is most likely the rapid decompression on takeoff—decompression from sea level to 8,000 feet in a matter of seconds—that causes the clots and this explains why flight attendants and other active members of the cabin have the same problem as the rest of us. It’s not just long-haul flights either. It is now known that many short trips seem risky. This is likely due to pressure/decompression working to produce and loosen clots.
What is the best prevention? Wear compression stockings. Your doctor will be familiar with them and can recommend the right size and pressure for you. Drinking just 4 ounces of tomato juice has a powerful blood-thinning effect (for example, there is a brand called Cardioflow), along with drinking plenty of water and getting up every hour to walk around.
I have a feeling airlines will never deliver the truth. My friend is a long-haul pilot for a large parcel service and knows it, so why not break the news? It might save your life.