Chronic bronchitis is a key phenotype of chronic obstructive pulmonary disease (COPD), characterized by airway-centered inflammation and mucus overproduction. It develops from long-term exposure to harmful particles or gases, most commonly cigarette smoke, which triggers a persistent inflammatory response.Cellular and Structural ChangesInflammation initially affects the large bronchi and later the smaller airways, with infiltration by immune cells, including neutrophils, macrophages, and...

Emphysema, a major phenotype of chronic obstructive pulmonary disease (COPD), is characterized by irreversible destruction of alveolar walls and permanent enlargement of distal airspaces. Unlike chronic bronchitis, which primarily affects the airways, emphysema predominantly involves the lung parenchyma, where structural damage leads to airflow limitation.PathophysiologyIt most commonly results from prolonged exposure to cigarette smoke and other toxic gases, particularly cigarette smoke.

Chronic obstructive pulmonary disease is a common, preventable, and treatable respiratory disorder characterized by persistent symptoms and progressive airflow limitation. This limitation results from a combination of small-airway disease (obstructive bronchiolitis) and parenchymal destruction (emphysema), both driven by chronic inflammation from exposure to harmful particles or gases.The disease includes two main pathological entities: emphysema, marked by destruction of alveolar walls and...

Chronic Obstructive Pulmonary Disease, or COPD, is a long-term condition marked by persistent and only partially reversible airflow limitation. It involves two overlapping conditions—chronic bronchitis and emphysema—which often co-appear but differ in dominant symptoms and underlying mechanisms.Chronic Bronchitis FeaturesChronic bronchitis presents with a persistent productive cough and thick, sometimes purulent mucus due to airway inflammation, enlarged mucus glands, and goblet cell...

Asthma is a chronic inflammatory disorder of the airways characterized by variable airflow obstruction and heightened bronchial responsiveness to a wide range of triggers. The underlying inflammation leads to airway swelling, mucus hypersecretion, and smooth muscle constriction, all of which narrow the airway lumen and impede airflow. Clinically, asthma presents with recurrent episodes of wheezing, shortness of breath, chest tightness, and coughing, symptoms that typically vary in intensity and...

Atypical pneumonia, often caused by Mycoplasma pneumoniae, is a form of pulmonary infection that differs from the classical presentation of bacterial pneumonia in both its cause and clinical symptoms. Mycoplasma pneumoniae is a pleomorphic bacterium notable for its lack of a rigid cell wall. This structural characteristic imparts resistance to beta-lactam antibiotics and significantly influences the bacterium’s behavior within the human host.Other pathogens responsible for the disease include...