hayflick:

They should not do any of the following, because if they do, you’re doing it wrong.

• Ooze
• Swell
• Pus
• Lymph
• Bleed
• Tear
• Hurt in any way, shape or form
• Go bright red
• Or, even worse, purple.
• But if they’re yellow, they’re far too thin and you’re probably screwed.
• If they…

Guys, go read this. 
Yeah.
Do it.

I laughed a bit at the terms they used, but these guys/girls know their shit.