Learn about tonsillitis causes, symptoms like sore throat & swollen tonsils , diagnosis, and treatments for bacterial and viral infections. Tonsillitis is inflammation of the tonsils in the upper part of the throat. It can be acute or chronic. [8][9][2] Acute tonsillitis typically has a rapid onset. [10] Symptoms may include sore throat, fever, enlargement of the tonsils , trouble swallowing, and enlarged lymph nodes around the neck. [1][2] Complications include peritonsillar abscess (quinsy). [1][3] Tonsillitis is most commonly caused by a viral infection, and about 5% to 40% of cases are caused by a bacterial infection. [1][5 ... Symptoms Common symptoms of tonsillitis include: Red, swollen tonsils . White or yellow coating or patches on the tonsils . Sore throat. Trouble swallowing or painful swallowing. Fever. Enlarged, tender glands called lymph nodes in the neck. A scratchy, muffled or throaty voice. Bad breath. Stomachache. Neck pain or stiff neck. Headache. Discover the 10 common symptoms of tonsil issues, related diseases, and effective treatment options to ensure your throat stays healthy and free from infection.