Question: @Ciaran ,why do we have spots and pimples ?

Ciarán O'Brien answered on 17 Nov 2014:

Spots and pimples are annoying, aren’t they? Some can be insect bites, but most of them happen because of the following:

Usually, you get a spot or a pimple when some of the bacteria that live on your skin (don’t worry, they’re harmless) accidentally get shoved into one of your pores (where sweat comes out) or the little spaces in your skin where hairs come out (follicles) If they get in there, they quite like the extra warmth, and there’s very little oxygen in there too, and some of them start growing.

Those spaces aren’t supposed to have anything growing in them, and the bacteria take up too much space and set off your body’s defenses, and the skin around the bacteria becomes inflamed and pink or red. The growing bacteria in the little nook of your skin form a sticky off-white coloured blob, and this is the pus you often find in a pimple (although some of that would also be white blood cells from your body, that moved in to try and kill off the bacteria).

Your body starts to change somewhere between 12-14 (this is called puberty), and that can cause your skin to release more chemicals, mostly oily ones. The bacteria on your skin love that stuff, and can find their way into more nooks and crannies in your skin because of it, and as a result teenagers can sometimes get a lot more spots and pimples than younger children or grown-ups.