Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease that causes obstructed airflow from the lungs. Symptoms include breathing difficulty, cough, mucus (sputum) production and wheezing.

Stages of COPD

• Stage I (Early)

• Stage II (Moderate)

• Stage III (Severe)

• Stage IV (Very Severe)

Smoking. Smoking is the main cause of COPD and is thought to be responsible for around 9 in every 10 cases. The harmful chemicals in smoke can damage the lining of the lungs and airways. Stopping smoking can help prevent COPD from getting worse.

Asthma and COPD are both chronic lung diseases. COPD is mainly due to damage caused by smoking, while asthma is due to an inflammatory reaction. COPD is a progressive disease, while allergic reactions of asthma can be reversible.