How do cuts and scratches heal?

You are chopping up vegetables for tonight’s dinner when the knife slips and you cut your finger. Cuts, scratches, and abrasions are injuries that can happen fairly easy. They differ from each other slightly. A cut is a slice through the skin that leaves an open gash. A scratch is like a cut, but only through the top layers of skin, not causing an open gash. An abrasion is a scrape that happens when the skin is rubbed away, like carpet burn.

After getting a cut, scratch, or abrasion, your skin may start to bleed. This happens because the injury breaks or tears tiny blood vessels that are found just under the skin’s surface. Your body wants to stop the bleeding, so it sends platelets.

At the site of the wound, platelets stick together like glue. This is called clotting, which works like a plug to keep blood and other fluids from leaking out. A scab, a hardened and dried clot, forms a crust over the wound. This protects the area under the scab so it can have time to heal.

Underneath the scab, new skin cells multiply to repair the wound. Damaged blood cells are repaired, and infection fighting white blood cells attack any germs that may have gotten into the wound. You aren’t able to see under the scab, but a new layer of skin is forming. When the new skin is ready, the scab falls off, usually within a week or two. If you pick at a scab, the new skin underneath can be ripped and the wound will take longer to heal. Picking at a scab can also cause scars to form.