Postnasal drip occurs when excess mucus accumulates in the back of the throat, leading to discomfort and coughing. While it is often associated with minor conditions like allergies or sinus congestion, many wonder whether postnasal drip could signal a respiratory infection. Postnasal drip can sometimes be a symptom of an underlying disease, such as a cold, flu, or bacterial sinusitis. However, it is essential to differentiate between infections and other causes of postnasal drip to ...