What happens to your skin after you cut yourself?
Maybe the best way to get your head around the importance of properly treating a cut is to think of it as a laceration, the medical term for an injury that results in a break in the skin. That sounds way more serious, doesn't it? Indeed, some deep cuts, like the kind you get from being tossed through a window or slashed with a knife, can really wreck your body and slice into muscles, tendons and ligaments, blood vessels and nerves. If you've got a big laceration that's bleeding and has a sharp object still stuck in it, call 911 immediately [source: Heller].
That much shallower boo-boo on your arm or leg isn't as much of a menace. But even a small cut can cause you significant discomfort, and cuts are a convenient way for a nasty bacteria such as Staphylococcus ("staph") to get into your body, which can lead to an infection [source: Gelfand]. A cut can also leave an ugly-looking scar, especially if it doesn't heal properly.
Once you cut yourself, your skin goes through a multi-stage process of regeneration. First, there's the inflammatory phase, when your skin goes into overdrive to prevent further damage. The blood vessels narrow, and the blood coming out of the wound clots to stop the flow. Your body releases a flood of chemicals that start the healing process, and specialized cells clear the wound of debris over the next several days. Your body also begins a process called epithelialization, in which new skin cells are created to form a protective barrier against bacteria and retain water. Next, there's the proliferative phase, in which you make a lattice of more skin cells and small blood vessels known as capillaries that give the wound its purplish-pink appearance and supply oxygen and nutrients so that the cells can produce proteins. (One of them is collagen, which is what scars are mostly made of.) After two to three weeks, the remodeling phase begins, as the replacement layer becomes stronger and more normal in color. Over the next six months, your replacement skin will become 70 percent as strong as your original hide [source: Durkin].
In the next section, we'll look at why you shouldn't put your regular moisturizer on a cut.