Different Virus

[breadstick]

Hi

My son recently had tonsillitis I then developed a horrendous batch of about 7 mouth ulcers and felt really run down, is it likely this is the same virus and also why do such things manifest themselves in different ways eg tonsillitis or what I had or a bad cold is their a virus hierarchy 

[bookbinder]

https://www.nhs.uk/conditions/mouth-ulcers/