Which of the following is a common symptom of bronchitis?

A persistent cough is commonly associated with bronchitis due to the inflammation of the bronchial tubes, which are responsible for carrying air to and from the lungs. When these tubes become inflamed or irritated, it triggers a reflex that results in a cough as the body attempts to clear thickened mucus and irritants. This symptom is particularly significant because it can distinguish bronchitis from other respiratory issues, where a persistent cough typically indicates an ongoing problem with the respiratory system.

Additional symptoms such as fever and chills or rapid heart rate may be present but are not exclusive to bronchitis and can occur in various other conditions. Joint pain is generally unrelated to bronchitis and more likely linked to conditions affecting the musculoskeletal system. Therefore, the persistent cough serves as a hallmark symptom, clearly indicating the presence of bronchitis.