The bacteria that helps cause spots is often a ‘friendly’ (i.e. not harmful) bacteria found inside our own bodies – one of the most common spot causing bacteria is called Staphylococcus aureus. Basically spots form when our hair follicles (tiny pouches in the skin) get blocked – remember that we have very thin, fine hairs all over our bodies, not just in places where the hair is obvious. When we reach puberty our hormones kick off and often cause our bodies to make too much ‘sebum’, a fatty substance that can make our hair and skin greasy. The extra sebum blocks the little hair follicles causing bacteria to build up under the skin. As the pressure in the blocked hair follicle increases it gets red and inflamed and the bacteria starts to spread into the cells around the follicle, creating pus. Nice!
Unfortunately, when we pick or squeeze spots we open up the hair follicle to even more bacteria, making the spot even more infected. Luckily we can’t catch spots from one another and everyone gets them sometimes so spots aren’t all that bad. They normally clear up once our hormones settle down.