A pharyngeal swab is actually a long, sterilized swab with no bacteria present on the surface. The main purpose of a pharyngeal swab is to take secretions from the pharynx and tonsils for bacterial culture and drug sensitivity testing. Under normal circumstances, the pharynx has a variety of flora, mainly because breathing and food need to pass through the mouth, and some of the bacteria will be stored inside. When an infectious disease occurs, it is best to send a pharyngeal swab for bacterial culture and drug sensitivity testing, which can detect the type of disease-causing bacteria and select the most sensitive class of drugs according to the test results, and also distinguish whether it is a bacterial infection or an anaerobic infection or a fungal infection. If there is no obvious pathogenic bacteria in the throat swab, it may be caused by viral infections, so there is no need to use antibacterial agents and pay attention to maintaining oral hygiene.