A sore throat is an inflammation or infection of the pharynx. The pharynx is the part of the throat between the tonsils and the larynx, or voice box.
A sore throat usually comes on suddenly, and is called acute. Some people have an ongoing, or chronic, form of the condition.
A sore throat can occur in viral infections such as the common cold, influenza, and infectious mononucleosis. Another cause may be bacteria such as Group A Streptococcus. This kind of sore throat is often called strep throat.
Sexually transmitted diseases such as gonorrhea can cause sore throat. A chronic sore throat may be caused by constant irritation from smoking, breathing heavily polluted air, consuming too much alcohol, or by swallowing substances that scald or scratch the throat.