What is the medical abbreviation meaning units?

UNIT has many different uses in medical terminology. It can be used to refer to "ONE" of a certain drug, vaccine or liquid volume or other agent necessary to produce a specific effect as in it took 4 units of blood for replacement during a surgery. It can be used to break time into segments like in anesthesia, 1 hour is 4 units with each unit being 15 minutes. In medical billing, 1 unit can be 1 day in a hospital or nursing facility. It can also represent a beginning amount and each additional amount of body surface area such as debridement of burns. For example, the first 10 sq. cm. of skin is the first unit and each additional 10 sq. cm. (or less or more) can be the next unit or units.