Chronic obstructive pulmonary disease (COPD) refers to a group of lung diseases that block airflow and make breathing difficult. 
Emphysema and chronic bronchitis are the two most common conditions that make up COPD. Chronic bronchitis is an inflammation of the lining of your bronchial tubes, which carry air to and from your lungs. Emphysema occurs when the air sacs (alveoli) at the end of the smallest air passages (bronchioles) in the lungs are gradually destroyed.

Damage to your lungs from COPD can’t be reversed, but treatment can help control symptoms and minimize further damage.
Symptoms of COPD often don’t appear until significant lung damage has occurred, and they usually worsen over time. For chronic bronchitis, the main symptom is a cough that you have at least three months a year for two consecutive years.

Other signs and symptoms of COPD include:

-Shortness of breath, particularly during physical activities


-Chest tightness

-Having to clear your throat first thing in the morning, due to excess mucus in your lungs

-A chronic cough that produces sputum that may be clear, white, yellow or greenish

-Blueness of the lips or fingernail beds (cyanosis)

-Frequent respiratory infections

-Lack of energy

-Unintended weight loss (in later stages) 
People with COPD are also likely to experience episodes called exacerbations, during which their symptoms become worse and persist for days or longer.