A recent study in Lancet Infectious Disease reminds us that most "lower respiratory tract infections" - coughs of less than 28 days duration, or "bronchitis" - do not benefit from antibiotics, which of course carry a slight degree of risk. I remember the first two clinical pearls I learned after my training were first that the color of mucus (nasal, coughed, or otherwise) indicates nothing about the cause of the mucus. Green mucus does not mean that you have a bacterial infection but only that the mucus has had a chance to dry in the airways before being expelled. The second pearl came from my own bout with bronchitis. I learned that coughs can truly linger without being pneumonia and without requiring antibiotics. Read here for reminders about treating persistent coughs by strengthening your own health.