What is Bladder Distension?

Home Medically Reviewed by Brooke Amar, RN

Bladder distension is a medical condition in which the bladder is stretched. This is usually due to urinary retention, in which the patient is unable to urinate, but it can be artificially induced by doctors in order to conduct tests for interstitial cystitis. These tests inflate the bladder with water so that the doctor can insert a cytoscope to view the patient's bladder wall. Bladder distension may be symptomatic of another medical condition and often presents with pain or discomfort and the urge to urinate, without the ability to do so. A patient will often complain of incontinence and leaking small amounts of urine, without relieving the urge to urinate.

The bladder is an elastic, muscular organ located on top of the pelvic floor that stores urine from the kidney until it is ready to be excreted through the urethra. Generally, the urge to urinate is experienced when the bladder is twenty-five percent full. When the bladder becomes full, the muscles in the bladder contract and a sphincter opens to let the urine vacate through the urethra and out of the body. If the bladder fails to let urine out, it can lead to pain, excessive stretching, incontinence, tearing, rupture, and the passage of urine back into the ureters and into the kidneys. The more severe complications can lead to sepsis and kidney failure, so bladder distension should be brought to immediate medical attention.

Bladder distension can be caused by a variety of conditions and is more common in men than women. Neurological damage can cause the muscles to not react properly or at all. Detrusor sphincter dyssynergia (DSD), for example, results from spinal damage or a neurological disease, such as multiple sclerosis (MS), and causes the sphincter to not coordinate with the bladder's contractions. Bladder scarring from previous surgeries can also cause an inability to urinate. A blockage of the urethra such as from a cyst, an STD lesion (usually gonorrhea) in men, or a congenital defect, can also cause bladder distension. It may also be a sign of prostate cancer or tumor. Urinary retention has been associated with pelvic infection, the use of psychoactive or anticholinergic drugs, and occasionally with forceful anal sex.

To test for bladder distension, a doctor or nurse will commonly ask the patient to lie on her back. The doctor or nurse will then tap on the lower abdomen, beginning at the symphysis pubis, the cartilaginous joint above the clitoris on women and above the penis on men, and continue to percuss the abdomen towards the umbilicus, or belly button. If the patient has a distended, urine-filled bladder, it will make a palpable dull sound. If the patient is not able to urinate after a period of time, the patient will likely be catheterized to relieve the bladder and prevent further complications such as shortness of breath, low blood pressure, high blood pressure, excessive sweating, pain, and tearing of the bladder.

The catheter will drain urine from the bladder into a bag and the doctor will then test for the cause of the bladder distention. Common tests include blood tests to look for infection and prostate specific antigens, samples of vaginal or penis secretions to check for infection, samples of urine for signs of bladder irritation, stones, or infection, and rectal exams, to check the condition of the prostate. A doctor may also a conduct magnetic resonance imaging (MRI) scan or a computed tomography (CT) scan to determine whether the cause is neurological.