In adult patients presenting with an acute onset of cough, what is the most frequent underlying cause?

- The most common cause of an acute onset of cough in adults is a viral upper respiratory tract infection (URTI).
- These infections are typically caused by viruses such as rhinoviruses, coronaviruses, and influenza viruses. They cause inflammation of the upper airway mucosa, which triggers a cough.
- Unlike bacterial infections such as pneumonia, viral URTIs generally present with a short duration of illness, a non-productive (dry) cough, and absence of focal chest signs.
- One common manifestation of such viral infection is acute bronchitis.