Drains are used for two reasons. One is to remove fluid, such as serum or blood, that would otherwise collect under the skin. The other reason is to pull the skin against the underlying tissue to allow it to stick in place. If drains are needed for your operation your doctor will usually tell you before surgery. Sometimes unusual circumstances arise and the surgeon will use a drain in a situation in which it was not expected to use one. This is usually because of excessive bleeding in surgery. If you have drains that you need to look after you will be given instructions on their care before you go home.