Chronic rhinosinusitis means a condition that lasts for at least 12 weeks and has at least two of the following symptoms: 1. Nasal congestion 2. Runny nose or post-nasal drip 3. Facial pain, facial pressure, or "fullness" 4. Sense of smell reduction. Acute rhinosinusitis is a temporary infection of the sinuses, usually caused by the common cold. Chronic rhinosinusitis is a more persistent problem that occurs following the common cold and requires a specific therapeutic approach. Because its symptoms are of a lower grade, it can be ignored by both patients and healthcare providers.

Source: http://www.kbb.org.tr