A wound is an injury that causes either an internal or external break in body tissue. An open wound (as in a knife cut) is a break in the skin or mucous membrane.

The most common accidents resulting in open wounds are falls, mishandling of sharp objects, accidents with tools or machinery, and car accidents.

A closed wound (a contusion or internal bleeding) is a bruise that damages the underlying tissue without breaking the skin (as in a black eye).

There are at least five different types of open...