why does puss come out like when we have a sore or like a bump that need to burst?

Question: why does puss come out like when we have a sore or like a bump that need to burst?
- Keywords:
  bump,
  puss,
  sore
Asked by Demetriana to Kevin, Jonathan on 25 Apr 2016.
- Jonathan Jackson answered on 25 Apr 2016:
  
  I think this is more Kevin’s area of expertise than mine!
- Kevin Baker answered on 25 Apr 2016:
  
  Hello Demetriana,
  
  Have you ever noticed that pus is mostly white? This is because it is made of white blood cells! White blood cells are actually colorless but they appear white in pus, which is how they got their name. These white blood cells are there to protect your body from germs that try to get you sick. Pus usually means you have an injury and your white blood cells go to protect it, so you get pus! It sometimes leaks out because of the pressure under your skin, there is so much pus that it breaks your skin!