A urinary catheter is a small, flexible tube that can be inserted
through the urethra and into the bladder, allowing urine to drain. The urethra
is the tube that carries urine outside the body from the bladder.
A urinary catheter may be used for someone who is unable to urinate
or who has difficulty moving and getting to the bathroom. It is also used to
collect a urine sample from someone who is very ill or unable to provide a
clean-catch urine specimen. Catheterization reduces the risk that the sample
will be contaminated.