If the incision is left exposed, it will heal by filling up the gaps from the bottom and sides. Depending on the size of the incision, an unstitched wound may take 1 to 4 weeks to heal. You will almost certainly have a noticeable scar. However, if you have thin skin or are prone to infections, it may require medical help before the wound closes completely. In general, wounds that reach the deep layers of tissue will need to be stitched. Stitching helps prevent leakage of blood and other fluids from the wound site as well as reduces pain. Some wounds may also be covered with dressing materials until they heal. Wounds that do not receive proper attention may become infected. Infections can cause serious problems if they spread to other parts of the body. Some common signs of an infection include bad odor, swelling, irritation around the wound site, and lack of healing. If you suspect that you have an infection, see your doctor immediately so that appropriate treatment can be given.