Which condition is characterized by difficulty in breathing due to bronchoconstriction?

• A. Chronic bronchitis
• B. Asthma
• C. Pulmonary embolism
• D. Pneumonia

Answer: (B)

Bronchoconstriction, which refers to the narrowing of the airways due to the tightening of surrounding smooth muscle, is a primary characteristic of asthma. In this condition, various triggers such as allergens, exercise, or irritants can lead to inflammation and mucus production in the airways, making breathing difficult. Individuals with asthma may experience wheezing, chest tightness, and shortness of breath as the airways become constricted.

Chronic bronchitis, while associated with a chronic cough and increased mucus production due to inflammation of the bronchial tubes, primarily involves obstruction due to mucus buildup rather than acute bronchoconstriction. Pulmonary embolism, on the other hand, is a blockage in the pulmonary arteries, typically caused by blood clots, leading to sharp chest pain and difficulty breathing, but not specifically due to bronchoconstriction. Finally, pneumonia involves infection and inflammation of the air sacs in the lungs, resulting in symptoms such as cough, fever, and difficulty breathing due to fluid and inflammatory exudate filling the alveoli, rather than bronchoconstriction. Thus, asthma is uniquely characterized by the acute episodes of bronchoconstriction that lead to the symptoms identified.