Looking to pack your bags and head to a paradise island filled with sunshine and and never-ending cocktails?

While rising above the clouds to your favourite destinations might seem the best thing that could happen to you, for your body it’s not so much fun.

And here are a few rather scary reasons why.

1. You will definitely feel dehydrated

Things that happen to your body when you fly on a plane: Dry skin
Your body will dry up (Thinkstock)

Feel your skin drying up and hair getting rough? That’s because our bodies are designed to feel comfortable when humidity is about 40% to 70%.

But in an aircraft, cabin humidity falls to about 20% and can even be as low as 10%. The recirculated air on planes suck the moisture from your skin, dry your eyes, throat and nose, and in extreme cases, your body could become seriously dehydrated.

Tip: To stay on the safe side, drink plenty of water – before and during and after your flight.

2. You could be drinking toxic water

Things that happen to your body when you fly on a plane: Drinking water
Avoid drinking aeroplane water (Thinkstock)

Thinking of having a cuppa on the plane? Think again.

An NBC5 investigation revealed that research by Environmental Protection Agency found 15 percent of the water on planes contained faecal matter and harmful bacteria such as E.coli.

“There’s poop in the water if there’s E. coli in the water, and that’s not a good thing,” Brenda Wiles, who manages a lab certified to test aircraft drinking water, told NBC5.

That makes using water from the bathroom tap to wash your hands more harmful than helpful.

Tip: Carry antibacterial wipes and don’t even think of drinking water unless it’s bottled.

3. You may feel discomfort in your ears

Things that happen to your body when you fly on a plane: Pressure in your ears
Breathing deeply could help pop your ears (Thinkstock)

Although the cabin is pressurised, the maximum pressure is much lower than you would experience at ground level.

As you ascend the air inside your ears expand, creating pressure within the ear canal. If this pressure cannot be released, due to a blockage from a cold for example, it can cause severe ear pain.

Tip: Swallowing, sucking sweets, breathing and yawning could help to “pop” your ears.

4. You could expose yourself to possible hearing loss

Things that happen to your body when you fly on a plane: Exposure to noise
Carry noise-cancelling headphones (Thinkstock)

If you are on a flight for more than four hours, depending on where you are sitting, you could inadvertently be exposing yourself to permanent hearing loss.

The National Institute for Occupational Safety and Health has set the safety limit at 88 decibels for four hours and 85 decibels for eight hours – and noise on a plane usually ranges between 95 and 115 decibels. And some of us may even add a few extra decibels on our headsets to block out the ambient noise making things even worse for ourselves.

Tip: Use noise-reducing headphones, which can cut noise by up to 40 decibels.

5. You might struggle with breathing

Things that happen to your body when you fly on a plane: Breathing problems
High altitudes mean there is less oxygen to breathe (Thinkstock)

Flying at high altitudes (planes typically fly at 35,000 feet or so) means the oxygen levels are much lower in the plane’s pressurized air, which can lead to minor oxygen deprivation – condition known as hypoxia.

Less oxygen available means your body has to work harder to get the required amount of oxygen into the bloodstream. Over time, this can lead to lightheadedness and shallow breathing as well as difficulty in concentrating and possibly aching joints.

Tip: Sadly, there’s not much you can do about this. Don’t drink alcohol as it harms your metabolism and makes the cells in your body less efficient in absorbing oxygen.

6. You could suffer from the ‘economy class syndrome’

Things that happen to your body when you fly on a plane: Economy class syndrome
Cramped environments are not good for blood circulation (Thinkstock)

All that sitting around for long periods in a cramped space could lead to blood pooling in your legs and feet, causing deep vein thrombosis, or DVT (also known as economy class syndrome) which can be potentially fatal.

DVT is a blood clot that forms in a deep vein in the body, usually in the lower leg or thigh. This clot can block blood flow to the leg, or even worse, break off and travel through the bloodstream to the lungs, cutting off blood supply.

Tip: Stand up and stretch your legs when possible. Try wearing support stockings might also help keep blood circulating through the legs.

7. You might suffer from constipation

Things that happen to your body when you fly on a plane: Constipation
Constipation is uncomfortable, especially on a plane (Thinkstock)

Long periods of sitting also slows down your metabolic rate and digestion – causing bloating and constipation.

Also, the gas in your intestines will expand as the plane rises and cabin pressure drops, causing you to feel pain and, er, fart more often.

Tip: Cut down on your calorie intake and twist from side to side in your seat to help everything keep moving.

8. You will almost certainly have bad breath

Things that happen to your body when you fly on a plane.: Bad breath
Bad breath is a common problem (Thinkstock)

Like metabolism and digestion, other systems in our body tend to slow down when we are flying and that includes saliva production – which plays an important role in preventing dental plaque build-up and bacteria thriving on the teeth.

Tiny food particles left in the mouth are assimilated by the bacteria in your mouth to release sulphur – a compound that causes bad breath.

Tip: Brush your teeth after meals and carry a pack of emergency mints.

9. You will be exposed to cosmic radiation

Things that happen to your body when you fly on a plane.: Cosmic radiation
You will be exposed to small amounts of radiation (Thinkstock)

Although the levels are low, you will be exposed to small amounts of radiation while flying. If you are on a long-haul flight and flying close to the North Pole, you will be more exposed to cosmic UV rays, which are energetic particles from space.

A recent scientific review by the Melanoma Program at UC San Francisco found that pilots and flight attendants have a much higher risk of developing melanoma compared to the general population and a 42 per cent higher melanoma death rate.

Tip: There isn’t much you can do about this, but take short-haul flights if possible. And keep the windows shut when you can to avoid sun trap.

10. You could suffer from ‘the bends’ if you’ve been diving

Things that happen to your body when you fly on a plane: Decompression sickness from scuba diving
Do not fly immediately after diving (Thinkstock)

If you are a regular diver, you probably know it’s really dangerous to fly soon after going scuba diving.

That’s because rising to high altitudes to quickly can cause ‘the bends’ – also known as decompression sickness, which is a potentially fatal condition that causes headache, joint pain, fatigue and breathing problems.

Tip: You need to wait at least 48 hours after a dive of more than 15 metres depth before hopping onto a plane.

11. Your taste buds could go numb

Things that happen to your body when you fly on a plane: Losing sense of taste
Try spicy meals if you are up for it (Thinkstock)

If you are tucking into an in-flight meal and finding it totally bland, maybe it’s you and not the food. Hard to believe?

Apparently, a study by Lufthansa found that dry air on planes evaporates nasal mucus, which essentially interferes with your olfactory senses and prevents you from enjoying your meal.

According to the study, passengers’ ability to taste sweetness and saltiness dropped as much as 30 per cent at high altitude.

Tip: If you have the option, go for spicy meals as they taste more strongly.

12. You are more prone to catching a cold

Things that happen to your body when you fly on a plane: Catching a cold or infection
Carry a nasal spray (Thinkstock)

Dry nasal mucus combined with a lot of strange people cramped into a single space means we are easy targets for the cold virus.

According to a 2004 study in the Journal of Environmental Health Research, the risk of catching a cold is over 100 times higher when you are flying.

Tip: Use a saline nasal solution to keep your nasal passages moist. It can act as a barrier to germs entering your body.

13. You’ll most likely suffer from a jet lag

Things that happen to your body when you fly on a plane.: Jetlag
Make sure you get adequate rest (Thinkstock)

Most travellers are quite familiar with the symptoms of jet lag.

The farther east or west you fly, the more disoriented you are likely to feel, though many people believe that the shortened nights that you suffer when flying west to east make things worse.

Tip: Try creating the right conditions when preparing for sleep – eyeshades and earplugs may help.