What are the potential red flags?

A patient comes in to see you complaining of a cough for three months. How does your assessment of this cough differ from a patient who has had a cough for five days? Tasks: What are the potential red flags? What is important not to miss in your review of systems? What are the differential diagnosis for a cough lasting three months? What are the top three causes of a cough lasting three months? Write a sample HPI for the above patient.