Lower,Upper Respiratory Tract Infection

A lower respiratory tract infection (RTI) occurs when there is an infection of the lungs, specifically in the lower airways. This infection is usually caused by a virus, but it can also be caused by bacteria or other less common organisms. Common lower RTIs in infants and young children include: Flu. An upper respiratory infection affects the upper part of your respiratory system, including your sinuses and throat. Upper respiratory infection symptoms include a runny nose, sore throat and cough. Treatment for upper respiratory infections often includes rest, fluids and over-the-counter pain relievers. Infections usually go away on their own.