A new study suggests asthma does more than just leave sufferers breathless; it also greatly increases the chances they'll suffer from other diseases, like obesity, pneumonia and anxiety disorders.

The new research from the Institute for Clinical Evaluative Sciences (ICES) has found that individuals with asthma see their doctor 72 per cent more often for other diseases compared to those who don't have asthma.

"Asthma is not just disease of the lungs -- it's a disease that affects other parts of the body," says lead author Andrea Gershon, an ICES Scientist and respirologist at Sunnybrook Health Sciences Centre in Toronto.

Gershon says because most asthma occurs in young people, who are usually thought to be healthy, it's assumed that most asthma sufferers don't have other health problems.

But this study found that's not true. It looked at the medical records of over 12 million people in Ontario and found that people with asthma:

• ended up in the emergency room of hospitals more than twice as often as those with other illnesses
• were admitted to hospital 66 per cent more often for other medical problems than non-asthmatics.

Together, asthma and asthma-plus-other-diseases were found to be associated with:

• 6 per cent of the 2.2 million hospitalizations in Ontario a year,
• 9 per cent of the 4.7 million emergency room visits,
• 6 per cent of the 131.3 million ambulatory care visits in Ontario in 2005

Gershon says the impact that asthma had on hospitalization for other conditions surprised even her.

"We expected people to see their doctors more often, but we were surprised to see how much more people were seeing their doctors," she says.

Bill Swan, a Toronto man with asthma, says he knows how asthma can lead to other problems. His list of ailments also includes stomach problems and periods of anxiety.

"Sometimes it's related to the asthma and sometimes it's the drugs you take for the asthma," he says. "For a while, I took a drug that was new that ate away at the stomach lining. So I was 13 and I had an ulcer."

The new research found that those with asthma often have other respiratory diseases, psychiatric problems, bone and joint injuries and heart disease.

"Asthma affects other diseases and other diseases affect asthma," says Gershon.

Gershon says her findings suggest that doctors need to look at an asthma patient as a whole, rather than just at their lungs.

She also hopes it spurs doctors to help asthma patients get their condition under control, because so many of the other diseases are linked to poor asthma control.

"I hope by treating the diseases better, you can get their asthma under control, and keep them out of hospital, out of emergency departments, and doctor offices," she says.