What does catheter mean?
A catheter is a slender, typically flexible tube that doctors insert into the body to drain fluids, deliver medications, or gain access to internal structures. The most familiar type is the urinary catheter, passed through the urethra into the bladder to drain urine when a patient cannot do so unaided — common during surgery or hospital stays. Catheters are equally central to modern cardiology, where long, fine catheters are threaded through blood vessels to perform diagnostic tests and interventions such as angiograms and stent placement. The word belongs almost entirely to medical language and carries a clinical, matter-of-fact tone rather than any emotional connotation. It derives from the Greek kathienai, 'to let down', a reference to the way the tube descends into the body. Related forms include the verbs catheterize and catheterization, describing the act of inserting one. For patients and caregivers alike, understanding what a catheter does can ease anxiety about a routine but intimate procedure.
nounA thin, flexible tube inserted into the body to drain fluids, administer medication, or gain access to a vessel or cavity.
- A slender flexible tube inserted into the body, especially into the bladder through the urethra, to drain urine or deliver fluids or medications.
- A long fine tube passed into blood vessels during diagnostic or interventional procedures, as in cardiac catheterization.
"After surgery, the nurses monitored the catheter to make sure it was draining properly."
"The patient's urinary catheter was removed two days after the operation."
"During the angiogram, the cardiologist threaded a catheter up through an artery in the wrist."
Regular plural formed by adding -s; standard in all varieties of English.
"Sterile catheters are stocked in every ward of the hospital."
The word comes from Greek kathienai, meaning 'to let down' — because ancient physicians literally let the tube descend into the body to drain it.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of catheter
Catheter entered English in the early 17th century via Latin catheter and French cathétère, ultimately from Greek kathetēr, meaning 'something let down'. This noun derives from the verb kathienai, formed from kata- ('down') and hienai ('to send' or 'to throw'), reflecting the ancient practice of lowering a tube into the body to drain it. The same Greek verb root gives us catharsis and cathartic, which share the sense of purging or emptying. Modern derived forms such as catheterize and catheterization arose in the 19th and 20th centuries as medical techniques expanded.
Related word forms
How catheter is actually used
Strictly medical register; not used figuratively in ordinary speech. In everyday contexts, if no type is specified, listeners usually assume a urinary catheter. Plural: catheters.
Easily confused with catheter
A cathartic is a purging or laxative agent (or something emotionally cleansing), whereas a catheter is a tube inserted into the body for drainage or access.
A cannula is a small tube left in place to allow passage of fluid or instruments, often shorter and used differently from a catheter; note also that 'canula' is a misspelling of 'cannula'.