By Claudine Ryan.
Holidays are almost here. If this year’s holiday involves international travel then there’s no avoiding a long-haul plane flight.
So this means jumping on a plane, plugging in your headphones and settling down to binge-watch hours and hours of inflight entertainment. It also means long hours sitting in the same seat and not moving around.
But have you ever wondered about the potential health issues that may arise when you spend that amount of time in a tin can at 20,000 feet?
Long flight times have always been the case for any travel to or from Australia. Some of these will be even longer once Qantas starts flying direct from Perth to London in 2018. (In what will be one of the longest flights in the world.)
There’s no doubt long-haul flights are a concern when it comes to deep vein thrombosis (DVT), says deputy director at Baker IDI Research Institute Professor Karlheinz Peter.
The longer the flight, the greater the risk. Any flight longer than four hours poses a risk, but it’s those longer than 12 hours that are most problematic, Professor Peter said.
One study found your risk steps up every two hours you’re in the air.
He says airlines should do more to make passengers aware of the risk.
“They should put much more emphasis on saying, ‘when you fly with us, especially these long-haul flights, then you should really look at mobilising and, in between, stretching’,” Professor Peter said.
DVT is a blood clot that forms in the deep veins of the leg, either in the calf or thigh. Often people don’t know if they have a clot as they’ll have no outward signs of it, but DVT can cause a range of complications, such as pain, inflammation, swelling and ulcers.
The real danger is if the clot dislodges, travels through your circulatory system and blocks the main artery responsible for blood supply to the lungs. This is known as pulmonary embolism. If the clot is small it can cause lung damage. A large clot can stop blood flow altogether, which can be deadly.
Professor Peter said most travellers don’t appreciate how frequently DVT occurs as a result of a long-haul flight.
“It’s quite scary numbers. If you look at asymptomatic deep vein thrombosis [where there are no obvious signs], there are studies showing it occurs in up to 10 per cent of long-haul flights,” he said.
It’s true most of those people would not have any symptoms and won’t develop any complications, but having one episode of DVT means you’re much more likely to have it again.
“You might have small damage in the wall of the vein. So it makes it easier for the next immobilisation that you increase the risk slightly to have deep vein thrombosis ,” Professor Peters said.
Of those who do develop symptoms, Professor Peter said in most cases, the airline has no idea.
“In the classic, long-term flight, you will probably have one or two patients who get out of the flight and will develop symptoms within the first two or four weeks after the flight.
“Typically for airlines it doesn’t show up during the flight, it shows up after the flight and so they don’t collect these figures.”