The study of taste is still in the developing stage, and the pathogenesis of the disease has not yet been thoroughly studied. There are several possible causes: First, the most common is viral infection, which damages some of the nerves that innervate the sense of taste, leading to neuritis and causing a loss of taste. Second, the nerves that govern the sense of taste, such as the tympanic cord nerve innervates 2/3 of the sense of taste, often otitis media or surgery damaged the tympanic cord nerve, the sense of taste is reduced and lost. Third, other causes, such as central disease, damage to the central part of the sense of taste, will also cause loss of taste.