What is COPD?

Chronic Obstructive Pulmonary Disease (COPD) is an umbrella term used to describe progressive lung diseases including emphysema, chronic bronchitis, refractory (non-reversible) asthma, and some forms of bronchiectasis. This disease is characterised by increasing breathlessness.

With COPD, your lungs do not work as well as they once did and you find it more and more difficult to breathe. As the disease progresses, your symptoms tend to get worse and more damage occurs in the lungs. This damage is permanent.

Emphysema and Chronic bronchitis occurs when the tiny air sacs in your lungs, the alveoli break down and become larger. With the destruction of the alveoli, your lungs are less able to get oxygen out of the air and less effective at getting rid of carbon dioxide. The walls of the damaged air sacs are stretched and less flexible, so that air is trapped inside the lungs. When this happens the airways can become “flabby,” and don’t push out air as well, and because so much air is trapped in the lungs, your diaphragm (the muscle at the bottom of the lungs that acts like an accordion) can become shortened and unable to assist in breathing. Damaged air sacs trap air inside your lungs. You might feel that it’s hard to take a deep breath. Like old balloons, the tiny air sacs get stretched out of shape and break down. Old air gets trapped inside the air sacs so there is no room for new air to get in.


Chronic bronchitis is an inflammation of the airways. It results in coughing (with phlegm) that you have every day, which occurs often. The inflammation occurs when the tiny hair-like projections called cilia that line your bronchial tubes are damaged. Normal cilia help propel mucus up the bronchial tubes. But when cilia are damaged, it becomes harder to cough up mucus, which in turn causes more coughing, more irritation, and more mucus production. And that means your airways become swollen and clogged. The result is obstruction and increased shortness of breath. You might say you have a “smoker’s cough” or a cold that won’t go away. But it could be due to damaged airways that have gotten tight, swollen, and filled with mucus. These changes limit airflow in and out of your lungs. And, this makes it hard to breathe.


How common is COPD?

The importance of COPD as a global health problem cannot be overstated. According to the latest World Health Organisation (WHO) statistics (2005), approximately 210 million people suffer from COPD worldwide, and 5% of all deaths globally are estimated to be due to this disease. This corresponds to more than 3 million deaths annually, of which 90% are thought to occur in low and middle-income countries.

A more recent projection published by the WHO Global Burden of Disease Project indicates that COPD will be the 3rd leading cause of death globally by the year 2030.