What Do “Red Flag” or “Yellow Flag” Symptoms Mean?

Question by Yasuhiro Bando: What do “red flag” or “yellow flag” symptoms mean?
What do “red flag” or “yellow flag” symptoms mean?

Please, can anybody tell me what they mean?

Best answer:

Answer by Sophia
Basically, “red flag” symptoms are the biggest sign of a particular illness. “yellow flag” symptoms are the same just in a degree of less urgency.

Know better? Leave your own answer in the comments!