The distinction between different upper respiratory tract infections (URTIs) is loosely based on the location of the symptoms. The common cold primarily affects the nose, pharyngitis primarily affects the throat, and bronchitis primarily affects the lungs. The common cold is frequently defined as inflammation of the nose and may include varying amounts of throat inflammation. Self-diagnosis is common. Isolation of the actual viral agent involved is rarely performed. It is generally not possible to identify the specific virus through symptoms.