Urinary Retention National Kidney and Urologic Diseases Information Clearinghouse What is urinary retention? What is the urinary tract Urinary retention is the inability to and how does it work? empty the bladder completely. Urinary The urinary tract is the body’s drainage retention can be acute or chronic. Acute system for removing urine, which is urinary retention happens suddenly and composed of wastes and extra fluid. In lasts only a short time. People with acute order for normal urination to occur, all urinary retention cannot urinate at all, body parts in the urinary tract need to work even though they have a full bladder. together in the correct order. Acute urinary retention, a potentially life-threatening medical condition, Kidneys. The kidneys are two bean-shaped requires immediate emergency treatment. organs, each about the size of a fist. They Acute urinary retention can cause great are located just below the rib cage, one discomfort or pain. on each side of the spine. Every day, the kidneys filter about 120 to 150 quarts of Chronic urinary retention can be a long- blood to produce about 1 to 2 quarts of lasting medical condition. People with urine. The kidneys work around the clock; chronic urinary retention can urinate. a person does not control what they do. However, they do not completely empty all of the urine from their bladders. Ureters. Ureters are the thin tubes of Often people are not even aware they muscle—one on each side of the bladder— have this condition until they develop that carry urine from each of the kidneys to another problem, such as urinary the bladder. incontinence—loss of bladder control, Bladder. The bladder, located in the pelvis resulting in the accidental loss of urine— between the pelvic bones, is a hollow, or a urinary tract infection (UTI), muscular, balloon-shaped organ that an illness caused by harmful bacteria expands as it fills with urine. Although a growing in the urinary tract. person does not control kidney function, a person does control when the bladder empties. Bladder emptying is known as urination. The bladder stores urine until the person finds an appropriate time and place to urinate. A normal bladder acts like a reservoir and can hold 1.5 to 2 cups bladder is the bladder neck. The bladder of urine. How often a person needs to neck, composed of the second set of urinate depends on how quickly the kidneys muscles known as the internal sphincter, produce the urine that fills the bladder. helps urine stay in the bladder. The third The muscles of the bladder wall remain set of muscles is the pelvic floor muscles, relaxed while the bladder fills with urine. also referred to as the external sphincter, As the bladder fills to capacity, signals which surround and support the urethra. sent to the brain tell a person to find a To urinate, the brain signals the muscular toilet soon. During urination, the bladder bladder wall to tighten, squeezing urine empties through the urethra, located at the out of the bladder. At the same time, bottom of the bladder. the brain signals the sphincters to relax. Three sets of muscles work together like a As the sphincters relax, urine exits the dam, keeping urine in the bladder. bladder through the urethra. The first set is the muscles of the urethra itself. The area where the urethra joins the Kidney Ureter Bladder Prostate Urethra Male and female urinary tracts 2 Urinary Retention What causes urinary phase of growth begins around age 25 and continues during most of a man’s life. retention? Benign prostatic hyperplasia often occurs Urinary retention can result from with the second phase of growth. • obstruction of the urethra As the prostate enlarges, the gland presses • nerve problems against and pinches the urethra. The bladder wall becomes thicker. Eventually, • medications the bladder may weaken and lose the ability • weakened bladder muscles to empty completely, leaving some urine in the bladder. Obstruction of the Urethra Read more in Prostate Enlargement: Obstruction of the urethra causes urinary Benign Prostatic Hyperplasia at retention by blocking the normal urine www.urologic.niddk.nih.gov. flow out of the body. Conditions such as benign prostatic hyperplasia—also called Urethral stricture. A urethral stricture BPH—urethral stricture, urinary tract is a narrowing or closure of the urethra. stones, cystocele, rectocele, constipation, Causes of urethral stricture include and certain tumors and cancers can cause inflammation and scar tissue from surgery, an obstruction. disease, recurring UTIs, or injury. In men, a urethral stricture may result from Benign prostatic hyperplasia. For men prostatitis, scarring after an injury to the in their 50s and 60s, urinary retention is penis or perineum, or surgery for benign often caused by prostate enlargement due prostatic hyperplasia and prostate cancer. to benign prostatic hyperplasia. Benign Prostatitis is a frequently painful condition prostatic hyperplasia is a medical condition that involves inflammation of the prostate in which the prostate gland is enlarged and and sometimes the areas around the not cancerous. The prostate is a walnut- prostate. The perineum is the area between shaped gland that is part of the male the anus and the sex organs. Since men reproductive system. The gland surrounds have a longer urethra than women, urethral the urethra at the neck of the bladder. stricture is more common in men than The bladder neck is the area where the women.1 urethra joins the bladder. The prostate goes through two main periods of growth. Read more in Prostatitis: Inflammation of The first occurs early in puberty, when the Prostate at www.urologic.niddk.nih.gov. the prostate doubles in size. The second 1Urethral stricture. Mayo Clinic website. www.mayoclinic.org/urethral-stricture/about.html. Updated November 20, 2012. Accessed April 1, 2014. 3 Urinary Retention Surgery to correct pelvic organ prolapse, Rectocele. A rectocele is a bulging of the such as cystocele and rectocele, and urinary rectum into the vagina. A rectocele occurs incontinence can also cause urethral when the muscles and supportive tissues stricture. The urethral stricture often gets between a woman’s rectum and vagina better a few weeks after surgery. weaken and stretch, letting the rectum sag from its normal position and bulge into Urethral stricture and acute or chronic the vagina. The abnormal position of the urinary retention may occur when the rectum may cause it to press against and muscles surrounding the urethra do not pinch the urethra. relax. This condition happens mostly in women. Constipation. Constipation is a condition in which a person has fewer than three Urinary tract stones. Urinary tract stones bowel movements a week or has bowel develop from crystals that form in the urine movements with stools that are hard, dry, and build up on the inner surfaces of the and small, making them painful or difficult kidneys, ureters, or bladder. The stones to pass. A person with constipation may formed or lodged in the bladder may block feel bloated or have pain in the abdomen— the opening to the urethra. the area between the chest and hips. Some Cystocele. A cystocele is a bulging of the people with constipation often have to bladder into the vagina. A cystocele occurs strain to have a bowel movement. Hard when the muscles and supportive tissues stools in the rectum may push against the between a woman’s bladder and vagina bladder and urethra, causing the urethra weaken and stretch, letting the bladder sag to be pinched, especially if a rectocele is from its normal position and bulge into present. the vagina. The abnormal position of the Read more in Constipation at bladder may cause it to press against and www.digestive.niddk.nih.gov. pinch the urethra. Tumors and cancers. Tumors and Read more in Cystocele at cancerous tissues in the bladder or urethra www.urologic.niddk.nih.gov. can gradually expand and obstruct urine flow by pressing against and pinching the urethra or by blocking the bladder outlet. Tumors may be cancerous or noncancerous. 4 Urinary Retention Nerve Problems Many patients have urinary retention right Urinary retention can result from problems after surgery. During surgery, anesthesia with the nerves that control the bladder is often used to block pain signals in the and sphincters. Many events or conditions nerves, and fluid is given intravenously to can interfere with nerve signals between compensate for possible blood loss. The the brain and the bladder and sphincters. combination of anesthesia and intravenous If the nerves are damaged, the brain may (IV) fluid may result in a full bladder with not get the signal that the bladder is full. impaired nerve function, causing urinary Even when a person has a full bladder, the retention. Normal bladder nerve function bladder muscles that squeeze urine out may usually returns once anesthesia wears off. not get the signal to push, or the sphincters The patient will then be able to empty the may not get the signal to relax. People bladder completely. of all ages can have nerve problems that Medications interfere with bladder function. Some of the most common causes of nerve problems Various classes of medications can cause include urinary retention by interfering with nerve signals to the bladder and prostate. These • vaginal childbirth medications include • brain or spinal cord infections or • antihistamines to treat allergies injuries − cetirizine (Zyrtec) • diabetes − chlorpheniramine (Chlor-Trimeton) • stroke − diphenhydramine (Benadryl) • multiple sclerosis − fexofenadine (Allegra) • pelvic injury or trauma • anticholinergics/antispasmodics to • heavy metal poisoning treat stomach cramps, muscle spasms, In addition, some children are born with and urinary incontinence defects that affect the coordination of nerve − hyoscyamine (Levbid) signals among the bladder, spinal cord, and brain.