what causes a prolongs soar throat
Several conditions can cause a sore throat. Sore throats may be caused by a viral illness, such as: 1  The common cold, the most common type of viral infection. 2  Infection of the voice box (laryngitis).3  Mononucleosis (mono, the kissing disease), a viral infection that tends to cause a persistent sore throat. The common cold, the most common type of viral infection. 2  Infection of the voice box (laryngitis). 3  Mononucleosis (mono, the kissing disease), a viral infection that tends to cause a persistent sore throat.