Hello,
A sore throat can have many causes. Common viruses, and even
the viruses that cause mononucleosis (mono) and
the flu, can cause a sore throat. Sinus drainage (post nasal drip) and bacteria. like streptococcus can cause a sore throat.
Are you taking some medicines or antibiotics? Sore throat appearing after treatment with antibiotics, chemotherapy, or other immune-compromising medications may be due to Candida, commonly known as "thrush.