OVERVIEW
Upper respiratory infection (URI) is a general term that refers to any infection of the upper respiratory tract, which includes the sinuses, nose, and throat. URIs are usually caused by viruses, but they can also be caused by bacteria, fungi, or other organisms.
The most common symptoms of a URI include a runny nose, sneezing, congestion, and a sore throat. These symptoms can range from mild to severe, and they can last for a few days to a few weeks. URIs are the most common type of infections, and they are usually not serious.
However, in some cases, URIs can lead to more serious complications, such as pneumonia or bronchitis.