We all know about the big risk factors that pose a threat to our health -- smoking, drinking too much alcohol, not exercising enough, and countless others.
But new health risks regularly hit the headlines and, more often than not, they're things we don't immediately think of as being dangerous to our well-being.
We take a look at five recent health concerns and discover if they're really hazardous.
1. A glass of fruit juice a day increases diabetes risk
An in-depth study has shown that drinking just one glass of orange juice a day could significantly increase a person's risk of diabetes.
The American study followed the long-term health of 70,000 female nurses over an 18-year period.
It found that the women who had one glass of fruit juice a day increased their odds of developing Type 2 diabetes by 18pc. The researchers suggest that "caution should be observed in replacing some beverages with fruit juices in an effort to provide healthier options".
So while we're all keen to increase our daily fruit intake, should we be careful about loading up on juice?
"It's an interesting study and we already know that fruit juices have lots of natural sugars," says Sarah Keogh, consultant dietitian at the Albany Clinic.
"When you eat a whole fruit, it takes longer for the sugar to break down in the body but fruit juice comes into the blood stream much more quickly and can affect insulin levels.
"I wouldn't advise anyone to stop drinking fruit juice -- it's a fantastic source of vitamins and a good way to take in fluids. I'd recommend drinking fruit juice alongside a meal as food slows the absorption of the sugar into the blood stream."
2. Women wearing the wrong size bras are damaging their breasts
An ill-fitting bra does little to flatter a lady's figure but new research has shown that it can also cause fragile ligaments to become irreparably stretched.
A breast biomechanics research team at the University of Portsmouth has spent the past three years testing 50 bra designs on hundreds of women.
The team's research shows that some women cause themselves breast pain or discomfort by not buying the right size bra.
Rose Reilly, a bra fitter at Brown Thomas, says that as many as 70pc of customers coming to her are wearing the wrong bra size.
"Women tend to leave long gaps between getting measured when they should really be getting fitted for a bra every six months," she says.
"So many things can affect breast size -- medication, weight loss, weight gain and so on.
"The most common mistake that women make is wearing a bra that is too big around the back. This means that the bust falls forward and isn't getting enough support.
"Another common problem is not adjusting the straps properly to make sure the bra is fitting right.
"And sometimes women wear a bra where the cup size is too small and that can lead to the dreaded 'four boobs' look."
Wearing the correct bra size can improve the appearance of your figure.
It can also help hold back the sagging that gravity is trying its hardest to achieve.
The good news is that a new bra is being developed that will keep boobs even more firmly in their place.
The research team at the University of Portsmouth is designing a new, extra supportive bra made with moulded plastic that will go on sale in Europe later this year.
Most bras are designed to limit just vertical movement but this bra will also control movement from side to side.
3. Watching sport can be bad for your health
You would think that armchair sports spectators would be safer than those actually participating in the sports. But not according to one of Germany's top cardiologists, Dr Klaus Kallmayer.
"Sports enthusiasts, who prefer watching the proceedings from the sofa rather than engaging in physical activity themselves, should be aware that, statistically, the comfort of their living room is no safer than actually competing," he says.
He refers to the fact that during the 2006 World Cup, Germany reported nearly three times more heart attacks and other heart problems than usual figures show.
The incidence of heart attacks increased when Germany was playing its most crucial matches in the tournament.
"Of prime importance for triggering a stress-induced event is not the outcome of the event, such as a win or loss, but rather the intense strain and excitement experienced during the viewing of a dramatic event," says Dr Kallmayer.
Sports fanatics can literally put their life on the line for their favourite team.
Last year, a University of Maryland study found that men with serious health problems often delay going to the emergency department so they can finish watching a game on TV.
Because, as we all know, football isn't a matter of life and death -- it's much more important than that.
4. Drinking too much water can be dangerous
Last month, a mother-of-two in the UK was awarded £800,000 after suffering brain damage from a detox diet that involved her drinking four extra pints of water a day and reducing her salt intake.
Dawn Page successfully sued the nutritional therapist who had advised her to go on the 'Amazing Hydration Diet'.
And an inquest last month in the UK heard that a 44-year-old man had died from excessive water intake -- which causes a condition called hyponatremia -- after he drank 10 litres of water within eight hours in order to combat gum pain.
But while these are tragic cases, they are highly unusual and most people are in little danger of drinking too much water.
"No trained nutritionist would ever advise consuming too much of any liquid," says Sarah Keogh.
"If you drink too much water, it draws salt and other minerals out of the body and causes the brain to swell up.
"But we're talking about people drinking something like eight to 10 litres of water.
"In the first case of the lady, Dawn Page, she wasn't drinking a huge amount of water and would have been ok except that she also reduced her salt intake."
Sarah says the usual guideline of drinking eight glass of fluid everyday (roughly 1.5 to 2 litres) is a good one to stick to.
"That can be increased if you're doing lots of exercise or if it is particularly hot," she says. "Your fluid intake can also include things like tea, milk, and so on."
Once you are taking in enough fluids to replace those that are lost through everyday functions, such as sweating, there's no need to go to extremes with how much water you drink.
5. Having fat friends can boost your size
It's long been observed that loved-up couples tend to put on a few pounds after getting together but now the blame is also being put on overweight friends.
A research team at the University of Warwick analysed data on 27,000 people from across Europe and found that people are subconsciously influenced by the weight of those around them.
According to the researchers, people get caught up in a spiral of "imitative obesity" as they try to "keep up with the Joneses" on calories.
But isn't dumping your friends because they're carrying a few extra pounds a bit harsh?
A closer examination of your own eating habits and exercise routine might be warranted.
Or perhaps you're one of the fortunate few who are able to eat calorie-laden food without getting a spare tyre?
Your friends mightn't be blessed with the same genetic luck.