millimeter
Meaning of millimeter: Medical findings from skin lesions to blood vessel measurements are commonly sized in millimeters, a metric unit equal to one thousandth of a meter.
Definition of millimeter
A millimeter is a unit of length in the metric system, equal to one thousandth of a meter, or roughly the thickness of a sharp pencil point. It is a small enough unit to precisely describe the size of many structures and findings encountered in medicine.
Medical measurements, including the size of a mole, a tumor, or a blood vessel, are frequently reported in millimeters or in units derived from it, since many structures relevant to diagnosis and treatment fall within this small scale. One inch is equal to roughly twenty five millimeters.
Because a change of even a few millimeters can be clinically meaningful, such as growth in the size of a skin lesion or a tumor over time, precise measurement in millimeters is a routine part of describing physical examination findings and imaging results.
Used in a sentence
The lesion measured several millimeters in diameter on physical examination.
Good to know
Millimeter measurements recorded during an examination or imaging study serve as a precise reference point for comparison, so a small stated change over time can carry more significance than the same finding described only in general terms.
Word origin
Where “millimeter” comes from
Formed from Latin mille, meaning thousand, and Greek metron, meaning measure, describing the unit as one thousandth of the base meter.