When you get stitches, a doctor threads a needle through your wound and pulls it tight to close the skin. As the stitches hold the edges together, the wound becomes inflamed as new cells begin to repair the tissue. Afterwards, connective tissues and collagen start to create skin. Then, blood vessels form to nourish these developing tissues, filling in the area. And over a few weeks, the wound will have healed together and the stitches are removed.