can be caused by viral or bacterial infections, some related to sore throats or colds.
Viral Sore Throat. More than half of all sore throats are caused by viruses (known medically as viral pharyngitis). They are often the same viruses that cause the common cold, flu, a sinus infection (sinusitis), or other upper respiratory tract infections. Rhinovirus infections appear to be the most common reason for a sore throat.