To catheterize someone is to slide a thin, soft tube into the body so liquid can go in or, more often, come out. The tube itself is a catheter; this word is the doing-word — the act of putting that tube in. The picture most people meet first is a tube into the bladder, so urine can drain after an operation, or when a person cannot get up to pee. Doctors also catheterize a vein, a wound, or (in heart work) a blood vessel. It is hospital language, calm and clinical: you will hear it from nurses and in notes, not at the dinner table. British spelling is often catheterise. After the tube is in, we say the person is catheterized. Though actually, everyday staff talk is just as likely to be “put a catheter in” or, for the bladder, “put a catheter in / do the catheter” — the -ize verb is the tidy dictionary shape of that same job.

插導管、置放導管（醫院口語常就是導尿、插尿管）