Ureter

What it means

A ureter is a slim, muscular tube that drains urine from a kidney down to the bladder. You have two, one on each side, each about the width of a drinking straw. The kidneys constantly make urine, and the ureters carry it downward using gentle, rhythmic squeezing waves of their muscular walls, much like toothpaste being pushed along a tube. The urine collects in the bladder until you are ready to pass it.

Why it appears on a CT, MRI or X-ray report

Radiologists name the ureters when assessing the urinary system, especially when looking for the cause of flank or belly pain or blood in the urine. Reports often comment on whether each ureter is normal in calibre or whether it is dilated (widened). A widened ureter can signal something blocking the flow further down. Because the ureters are narrow, they are described carefully when a stone is suspected, since stones often lodge along their path.

What it usually means

In most reports the ureters are named simply to confirm they look normal, with phrases such as both ureters are of normal calibre. This is reassuring and means urine is draining freely from the kidneys. If a ureter is described as dilated, the radiologist is noting that it is wider than usual, which often points to something obstructing the flow lower down, most commonly a stone, but sometimes external pressure or narrowing. The report will usually try to identify the cause and may note any associated swelling of the kidney above. On its own, naming the ureters is descriptive. Their meaning depends on the surrounding findings, your symptoms, and why the scan was done.

When to follow up

The name alone needs no action. Pay attention to what is described about it. If your report notes a dilated ureter, a stone, an obstruction, or kidney swelling, discuss this with your doctor promptly. Symptoms that deserve urgent attention include severe one-sided flank or belly pain that comes in waves, blood in the urine, fever with urinary symptoms, or difficulty passing urine. These should be assessed by a clinician without delay.

A plain-language way to picture it

Think of each kidney as a small reservoir high up and the bladder as a holding tank below. The ureter is the narrow pipe connecting them, and its muscular walls squeeze in waves to push urine down, like slowly milking liquid through a flexible straw. When something plugs the pipe, such as a small stone, the fluid backs up behind it, which is what radiologists are watching for.