While pharyngitis itself isn't contagious, the underlying illness causing it might be contagious. Pharyngitis is another name for a sore throat, which is caused by swelling between the larynx and the tonsils at the back of the throat.
Most sore throats are caused by the flu or colds, but they can also be caused by other illnesses, such as mononucleosis, according to MedlinePlu, a service of the U.S. National Library of Medicine and the National Institutes of Health, A cold, the flu and mono are contagious. When the sore throat is caused by a contagious viral illness, antivirals might help. If the sore throat is brought on by a contagious bacterial infection such as strep throat, doctors typically prescribe antibiotics. Contagious illnesses that cause pharyngitis tend to occur mostly during the colder months. An easy way to prevent the spread of illnesses that cause pharyngitis is to keep common areas clean and disinfected.