Closed wounds are injuries where the skin remains intact, meaning there is no break in the surface. These types of wounds can occur from impacts, such as bruises or contusions, where blood vessels under the skin are damaged but the outer layer of skin is not. Closed wounds can also include injuries like sprains or strains, where muscles or ligaments are stretched or torn without any visible skin damage. While they may not be as immediately visible as open wounds, closed wounds can still cause pain, swelling, and bruising, and may require medical attention depending on their severity.