An Upper Respiratory Infection (URI) is a common illness that affects the nose, throat, and sinuses. It is often caused by viruses, such as the common cold or influenza, and can lead to symptoms like a runny nose, sore throat, cough, and sneezing. URIs are usually mild and resolve on their own within a week or two. While most URIs are viral, some can be caused by bacteria, leading to conditions like sinusitis or strep throat. Treatment typically focuses on relieving symptoms, such as using over-the-counter medications, staying hydrated, and resting. In severe cases, a healthcare provider may prescribe antibiotics if a bacterial infection is suspected.