What Are the Different Stages of COPD?
Chronic obstructive pulmonary disease, or COPD, is a progressively worsening disease that causes difficulty breathing. The disease includes chronic bronchitis, a chronic cough with mucus lasting at least three months, and emphysema, abnormal enlargement of the tiny air sacs inside the lungs resulting from destruction of the lining of the lungs. Chronic obstructive pulmonary disease develops slowly and may go untreated for years. Once symptoms appear, there is no known cure for the disease. Doctors classify progression of the disease into four different stages, based on the severity of the symptoms.
