This document provides information about acute and chronic pharyngitis. It discusses the anatomy of the pharynx and causes of acute pharyngitis such as viral and bacterial infections. Clinical features of acute pharyngitis are described along with investigations and treatment options. Complications are outlined. Acute tonsillitis is also discussed including types, symptoms, signs, and treatment. Chronic pharyngitis and conditions such as peritonsillar abscess, diphtheria, and retropharyngeal abscess are summarized as well.