If the patient’s throat becomes painful when swallowing saliva, the following causes are mainly considered: 1. There may be foreign bodies in the patient’s mouth or throat, and the patient has eaten fish or shrimp, or even chicken bones, which sometimes tend to lodge in the patient’s mucous membrane and lead to painful conditions. 2. 3. Consider patients with autoimmune system diseases or infectious diseases, such as HIV or syphilis, which sometimes lead to ulcers in the mucous membrane of the pharyngeal cavity and pain when the patient swallows saliva.