Asthma is a chronic condition that causes inflammation and narrowing of the airways in the lungs, leading to wheezing, chest tightness, shortness of breath, and coughing. These symptoms often occur in episodes, commonly referred to as asthma attacks, and can be triggered by factors such as allergens, cold air, exercise, strong emotions, and certain medications. While the exact cause of asthma remains unclear, both genetic and environmental factors appear to contribute.

Bronchitis is the inflammation of the bronchial tubes, which carry air to and from the lungs. This condition results in persistent coughing, often producing mucus, chest discomfort, and shortness of breath. Bronchitis can be acute, typically following a respiratory infection like the common cold or flu, or chronic, often caused by prolonged exposure to irritants such as smoking.

COPD refers to a group of lung diseases that obstruct airflow and make it harder to breathe. The two main conditions under COPD are emphysema and chronic bronchitis, both of which cause the lungs to lose their elasticity over time. Symptoms include wheezing, shortness of breath, and chest tightness. The primary cause of COPD is long-term exposure to lung irritants, most notably tobacco smoke.

Pneumonia is an infection that inflames the air sacs in one or both lungs, causing them to fill with fluid or pus. This inflammation can result in coughing with phlegm, fever, chills, and difficulty breathing. Pneumonia can be caused by bacteria, viruses, or fungi, with severity ranging from mild to severe, depending on the organism involved, the individual’s age, and their overall health.