With air pressure in the cabin similar to what you'd expect to find at 8,000 feet above sea level, your lungs have to work much harder to take in the same amount of oxygen, contributing to the headaches and dizziness that many people feel.
Dr Brewer, who partnered with UK-based airport parking operator and retailer, Airport Parking and Hotels (APH), advises: "Ensuring that you are well rested and drink plenty of non-alcoholic fluids before and during the journey will help minimise these effects, and help you adjust better to your new timezone."
Ankle swelling and deep vein thrombosis
Sitting still for extended periods of time has long been associated with Deep Vein Thrombosis (DVT), which kills thousands of people every year.
The condition occurs when blood clots develop within the deep veins of the legs, causing pain and swelling.
According to the American Heart Foundation, long periods of immobility in cramped spaces, low cabin pressure and dehydration can all contribute towards the likelihood of a passenger getting DVT.
But it can be prevented by wearing compression socks, below-the-knee stockings, loose clothing and moving around the cabin.
Hearing loss
Many of us are accustomed to the roar of an aircraft, even from inside the cabin.
Sounds can often range between 95 and 105 decibels, rising to 115 during take-off - which can potentially lead to hearing loss, especially if you fly a lot.
To safeguard your ears, invest in noise-cancelling earphones and avoid the rear of the plane which is usually louder.
Reduced taste
The blandness of plane food isn't down to its preparation at all but in-flight cabin pressure wreaking havoc with your tastebuds.
As the body is hit by rapidly changing air pressure and inhales dry cabin air, taste buds are numbed and nasal mucus membranes are dried, reducing taste by up to 30 per cent.
Tips to avoid this include: bringing a nasal spray, using decongestion tablets or chewing gum.
<2h>Bad breath
Dry and oxygen-deprived conditions in an aircraft cabin can dry your mouth out during a fight which causes bacteria to flourish.
To beat this try and eat healthy foods, drink lots of water and brush your teeth.
Illnesses
Aircraft cabins are a ripe breeding ground for viruses.
A study posted in the Journal of Environmental Health Research in 2004, revealed that the chance of developing the common cold is over 100 times greater on a flight than on ground level.
Avoid touching your eyes, nose and mouth and wash your hands to help prevent the spread of germs.
Constipation
Sitting down for long periods of time can make you constipated as your metabolic rate and digestion slows due to the inactivity.
You will probably also experience bloating and become gassy after long periods in the air.
Try drinking water (not alcohol or caffeinated drinks), and move your body from side to side in a twisting motion to help speed up your metabolic and digestive systems.
Motion sickness
Motion sickness can leave you looking pale, feeling dizzy and even nauseous.
It is caused by a difference between what your eyes see and what your inner ears -which are responsible for balance - feel.
Your inner ears think you are sitting still but your eyes know you're travelling at 500mph or that the aircraft is tilting.
It will normally go away after a while, however, but taking sickness medication can help as well as sitting still and looking at stable objects.
Fatigue and irritability
Feeling tired and short-tempered during a flight is common, especially when on a long-haul trip.
The further the distance travelled, the greater the disruption to your body clock and the worse the symptoms get.
But as Dr Brewer explains: "Jet lag is a result of a disturbance in the body's 24 hour sleep-wake biorhythms and is most likely to affect those who normally follow an established daily routine.
"If you're flying east, try going to bed earlier than usual for several nights before travelling. If you're going west, stay up later.
"It takes between half a day and two days to adjust to each time zone crossed and breaking up a very long journey with a stopover for rest can make it easier to adjust."
