(HealthDay News) — Chronic obstructive pulmonary disease (COPD) refers to a pair of chronic lung conditions — bronchitis or emphysema. Many people with COPD have both.

According to the American Lung Association, 80 percent to 90 percent of COPD-related deaths are attributed to smoking. Air pollution, exposure to secondhand smoke, and a childhood history of respiratory infections also are risk factors for COPD, as may be a person’s heredity.

People with COPD usually experience shortness of breath and difficulty exercising or working. Current medications for COPD do not slow progression of the disease, but can help tame symptoms.

Prescription drugs such as inhalers can improve breathing capacity by relaxing the lung airways. A doctor may also prescribe oxygen treatments, antibiotics or steroidal remedies.