A surgical drain is used to prevent fluids or infectious material from building up near or at the site of a surgery. It does exactly as it sounds: it drains blood and fluids out of the body just like plumbing drainage.
There are many types of post-surgical drain tubes. They range from chest tubes to keep fluid from building up around the heart after open surgery to small, bulb-type drains which apply gentle suction. You can attach the bulb to your clothing with a safety pin or secure it near the bandage.
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The type of surgery you have and what area of your body it will be performed on will determine the type of drain that you get. Depending on the problem, you may need one or more drains.
You must be careful after the surgery drain procedure and examine your wound each time you change the dressing. If any of these happen, call your doctor.