Chronic laryngitis is the chronic inflammation of the laryngeal mucosa which may involve submucously and the intralaryngeal muscular layer. The disease is mostly due to prolonged course of acute laryngitis without cure or the repeated occurrence of acute laryngitis. Prolonged improper methods of phonation or overuse of voice may result in the disease as well. Besides, the occurrence of the disease is also related to the stimulation of harmful gases or dust, heavy smoking and the spreading of inflammation of upper and low respiratory tracts, or the stimulation of secretion.

Pathologically, it manifests as chronic congestion of the laryngeal mucosa with angiectasis, interstitial edema, infiltration of lymphocyte and increased secretion of the mucous gland at the early stage. Then there exist hyperplasia and hyaloid degeneration of the fibrous tissue, pachynsis of mucosa, metaplasia and keratosis of epithelium mucosae, sticky and thick secretion of the mucous gland, even occurrence of polyp of the vocal fold or vocal nodules.