Prioritize (ABCD) rank Severe C vs Mild B

[Natasha A., CNA, LVN]

Hi, I am learning about ABCD's in nursing and

came across a rule that SEVERE Circulation

is higher priority than MILD Breathing.

What are examples of MILD breathing?

The only example I know for SEVERE C is dehydration.

What are other examples of Severe C?

Thank you!

Also, any good ER books to recommend? I came across "Triage Nursing Secrets"