As the problem of obesity has grown alarmingly in recent years, with about 65 percent of the US population now being classed as either overweight or obese, so too has the problem of asthma. Asthma, which results in recurrent wheezing, coughing and hypersensitivity to allergies, affects about 20 million Americans, including a staggering 9 million children.

So could the growing problem of asthma be linked to the rise in obesity?

In a recent study, which looked at the records of more than 330,000 patients in the US, Canada and Europe, it was found that as an individual's body mass index (BMI) passed 25 (the threshold for being overweight) so his or her chances of developing asthma increased by 50 percent. The study also found that as weight continued to increase so too did the risk of developing asthma.

The study also showed that this risk seemed to be equally distributed between both men and women and that there was no foundation for the previously held belief that there might be a connection between obesity and asthma in women but not in men.

Now if you are overweight and are experiencing breathing problems you should not immediately leap to the conclusion that you have asthma. Breathing problems can arise with increasing weight as your lung volume is effectively reduced, your chest wall is restricted or indeed for a variety of other reasons. However, if you are experiencing problems you should of course have these checked out by your doctor and should not be surprised if this does indeed turn out to be asthma.

Asthma is a chronic and incurable, but normally controllable, condition which produces an inflammation and narrowing of the airways leading to and from the lungs. What is not clear at this stage however is whether being overweight can actually cause asthma. Further research will be required but the best guess at the moment is that a substantial proportion of the population is in fact suffering from mild and undiagnosed asthma and that an increase in weight aggravates the condition and turns a mild case of asthma into severe asthma.

One the other side of coin the good news is that losing weigh could potentially reduce the problem significantly.