Baby boomers (Canadians aged 45 to 49) may be one of the hardest-hit groups, according to the survey, with one in seven possibly afflicted with COPD.
And 19 per cent of Canadians (4.9 million) are at risk of developing the disease, with one in 10 over 40 at risk.
The findings of the survey were released Tuesday. Undiagnosed COPD patients were identified through the lung test, a standardized disease predictor that consists of questions about a person's symptoms.
Chronic obstructive pulmonary disorder is a chronic lung disease that leads to lung damage and blockages of the airways. Its symptoms include a shortness of breath and decreasing activity levels. It is predominantly caused by smoking.
"Smoking is the number one cause of COPD and it is astounding that millions of Canadian who may have COPD haven't been tested," said Dr. Anna Day, director of the Gender Asthma and COPD Program at Women's College Hospital in Toronto, in a release.
Fifty-six per cent of all Canadian adults smoke or have smoked in the past, according to the data. Just under five million currently smoke while 9.5 million smoked at some point in the past.
But many don't believe that smoking plays any role in their current health. Forty-five per cent of those surveyed said they didn't think their smoking past would affect their health.
Day said people who suspect they have the condition should see a doctor who might advise them to undertake a spirometry test that assesses their breathing.
Spirometry (meaning the measuring of breath) is a common test to measure lung function. It can determine volume and/or flow of air that can be inhaled and exhaled.
The good news, however, say health experts, is that awareness of COPD is growing. The survey reveals that two-third of Canadians now report that they have heard of the disease and one-third are aware of the acronym.
From a provincial perspective, Nova Scotians are most aware of the disease, at 68 per cent, while Quebec is the least aware, at 43 per cent.
Women are more aware of COPD at 62 per cent versus 57 per cent of men.