The prefix "per-" means what?

The prefix "per-" is derived from Latin, meaning "through" or "completely." In medical terminology, it is often used to indicate movement through a structure or the expansive effect of a treatment or condition. For example, in terms like "percutaneous," the prefix suggests that a procedure is done through the skin. This conveys not just a sense of movement, but also emphasizes thoroughness or entirety.

The other options—after, before, and beside—represent different Latin prefixes such as "post-" for after, "pre-" for before, and "para-" for beside. Each of these has its distinct meanings, which do not apply in the context of the prefix "per-." Understanding these distinctions helps clarify the specific implications of medical terms that use the prefix in their composition.