Chronic obstructive pulmonary disease, or COPD, is the third leading cause of death worldwide according to the World Health Organization. COPD is a chronic inflammatory lung disease that causes obstructed airflow from the lungs. 

The main cause of COPD in developed countries is tobacco smoking. In the developing world, COPD often occurs in people exposed to fumes from burning fuel for cooking or heating in poorly ventilated homes. People with COPD are at increased risk of other diseases too, such as heart disease, lung cancer and a variety of other conditions. Although COPD is a progressive disease, it is also treatable. 

"If you catch it at an early phase, treatment may consist of helping the patient to stop smoking or taking the patient away from the polluted environment that may be contributing to the disease," says Dr. John Costello, a consultant pulmonologist at Mayo Clinic Healthcare in London. "For those with more advanced disease, long term rehabilitation programs have been very successful in centers that specialize in pulmonary disease."

As a part of rehabilitation, treatment for advanced COPD can include the use of medications, inhalers and oxygen therapy.

On the Mayo Clinic Q&A podcast, Dr. Costello discusses how COPD is diagnosed and the treatment options for COPD.