So many of us take regular medication on a day-to-day basis - the pill, blood pressure tablets, sleeping tablets - and we rarely even give it a second thought.
But The Conversation has revealed that some daily medication can actually become quite dangerous when taken on a flight due to the environmental conditions of the plane.
Writing about the possible dangers, Nial Wheate, said that planes are normally pressurised to the same atmospheric conditions that are found at 10,000 feet altitude.
Wheate said at that level, the effective oxygen level is only 14.3%, which is much lower than the 20.9% found at ground level.
Lack of movement and sitting in a cramped condition causes an additional risk of reduced blood flow, and on top of this, dehydration is caused by a lack of humidity in the air.
All of these factors combined, there is an increased risk of deep vein thrombosis(DVT), and some medications can up your chances of developing DVT even more.
1. Contraceptive pill & other hormone-based medication
There are some brands of the contraceptive pill that are understood to increase the chances of getting a blood clot.
As well as this, Hormone Replacement Therapy can have the same effect.
2. Sleeping tablets
Sleeping tablets can seem like a really handy option if you're heading off somewhere on a long-haul flight. But in reality, it's not such a good idea.
Taking sleeping pills cause you to fall asleep, of course, and this lack of movement when you're sleeping can increase your risk of DVT.
Some antihistamines have a drowsy affect on people. This may seem ideal when hopping on a flight, but these types of antihistamines are also known to depress breathing, which is not a good idea as you'll already have a lack of oxygen.
Although the likelihood that you'll get a blood clot while flying is very slim, it's still worth keeping in mind what medications can increase the risk, so you can choose to avoid them or at least wait until you've landed to take them.