What does the prefix "per-" mean?

The prefix "per-" means "through" or "by means of." It is commonly used in medical terminology to denote thoroughness, completeness, or a sense of going beyond a point. For example, in terms like "percutaneous," it indicates a procedure done through the skin. This usage reflects the idea of something being done in a direct or complete manner. Understanding this prefix helps in deciphering complex medical terms and their meanings, which is crucial in the healthcare field. The other options refer to different prefixes: "below," "before," and "across," which have their own specific meanings and uses, but do not align with the definition of "per-."