Your skin has tiny glands called 'sebaceous glands' that produce oil. When those glands produce too much oil, it can result in acne.
P. Acnes' is a type of bacteria that's present on most people's skin, even those without acne, but certain specific strains of it are known to cause acne.
Sometimes our pores can get clogged with dead skin and other debris. Luckily, washing and exfoliating your skin can do a lot to stop this!
This one's a bit tricky because doctors don't fully understand it yet; however, what we do know is that inflammation in the skin is often tied to acne.
If you're embarrassed by your acne, does that insecurity ever affect your performance at school?