Learn about Alexandra Michelle: her birthday, what she did before fame, her family life, fun trivia facts, popularity rankings, and more. Fun facts: before fame, family life, popularity rankings, and more.
Viruses cause such respiratory infections as the common cold (rhinovirus), the flu (influenza), some pneumonias and bronchiolitis (respiratory syncytial virus, or RSV). It can be difficult to determine whether you have a viral or bacterial infection because the symptoms are often similar.
Definition. 1  The common cold is a viral infection of the upper respiratory system, including the nose, throat, sinuses, eustachian tubes, trachea, larynx, and bronchial tubes. Although more than 200 different viruses can cause a cold, 30-50% are caused by a group known as rhinoviruses.