Common viruses, and Bacterial infections.
Causes. The tonsils are lymph nodes in the back of the mouth and top of the throat. They help to filter out bacteria and other germs to prevent infection in the body. A bacterial or viral infection can cause tonsillitis. Strep throat is a common cause. Tonsillitis can be caused by a virus, such as the common cold, or by a bacterial infection, such as strep throat. Children come into close contact with others at school and play, exposing them to a variety of viruses and bacteria. This makes them particularly vulnerable to the germs that cause tonsillitis. Symptoms of tonsillitis. Common tonsillitis symptoms include sore throat, visibly red and swollen tonsils, white patches on the tonsils, fever, headache, difficulty swallowing, stomach pain, loss of voice, enlarged lymph nodes in the neck and jaw, runny or stuffy nose, sneezing, and coughing. Symptoms include a sore throat, swollen tonsils, and fever. This condition can be caused by a variety of common viruses and bacteria and is contagious. If left untreated, tonsillitis caused by strep throat (Streptococcus bacteria) can lead to serious complications. Tonsillitis is easily diagnosed and treated. Inflamed tonsils. Tonsillitis is most often caused by common viruses, but bacterial infections can also be the cause. The most common bacterium causing tonsillitis is Streptococcus pyogenes (group A streptococcus), the bacterium that causes strep throat. Other strains of strep and other bacteria also may cause tonsillitis.
https://www.nlm.nih.gov/medlineplus/ency/article/001043.htm http://www.healthline.com/health/tonsillitis http://www.medicalnewstoday.com/articles/156497.php http://www.healthline.com/health/tonsillitis http://www.mayoclinic.org/diseases-conditions/tonsillitis/basics/causes/con-20023538
what causes tonsils