cc
Meaning of cc: Handwriting is the whole problem: a hurried cc reads as u, the old abbreviation for units, and the quantity changes entirely.
Definition of cc
Cc is an abbreviation for cubic centimeter, a metric unit of volume equal to one milliliter. A thousand of them make a liter. The abbreviation appears throughout older medical records for volumes of fluid, medication and drainage, though medication safety guidance now favors writing mL instead, because cc is easily misread when written by hand.
What volume does it represent?
A cubic centimeter is the space enclosed by a cube one centimeter along each edge. That space was defined to hold exactly one milliliter, so cc and mL name an identical quantity and never require conversion. One thousand cc make one liter. The two abbreviations arrived from different directions, one from geometry and one from the metric volume scale, and both settled into medical use for the same measurements: intravenous fluid rates, syringe volumes, urine output, drain output, and the volume of a mass on a scan.
| Written as | Equal to | Where it appears |
|---|---|---|
| cc | 1 mL | Older charts, syringe markings, ventilator settings |
| mL | 1 cc | The preferred written form in current records |
| L | 1000 cc | Large volumes, such as daily fluid totals |
Why is the abbreviation discouraged?
The objection is not to the unit but to the handwritten symbol. Written quickly, the two loops of cc can close up and read as a u, the old abbreviation for units. An order meant as a volume then reads as a number of units, and the two are not remotely the same quantity. Lists of error-prone abbreviations used in medication safety therefore place cc among the entries to avoid, with mL as the recommended replacement. Printed orders and electronic records have reduced the exposure, but the recommendation still applies wherever an entry is written out, and cc survives in older notes, on equipment displays and in everyday speech.
Does an older record need converting?
No. A fluid rate written in cc per hour means precisely what the same number in mL per hour means today, so an archived chart requires recognition rather than arithmetic. Syringe barrels and other calibrated devices still carry cc markings, and the unit remains standard outside medicine for engine displacement and container volumes. The ambiguity runs in only one direction: reading cubic centimeter where cc is written is unambiguous, while writing cc where mL is meant is the step that introduces risk.
Also known as
Used in a sentence
The order specified the intravenous fluid rate in cc per hour.
Good to know
Handwritten cc can be misread as u, the old abbreviation for units, which is why lists of error-prone abbreviations used in medication safety recommend writing mL in its place.