Inability to Urinate

eMedicineHealth: Experts for Everyday Emergencies

Inability to Urinate,
by Siamak T. Nabili, MD, MPH (author) and Melissa Conrad Stöppler, MD (editor)

Contents
  • Overview
  • Causes
    • Common Causes
    • Medication-related causes
    • Urinary retention in children
    • Other causes
  • Symptoms
  • When to Seek Medical Care
  • Exams and Tests
  • Inability to Urinate Treatment
    • Self-Care at Home
    • Medical Treatment
  • Next Steps
    • Medications
    • Follow-up
  • Prevention
  • Outlook
  • Authors and Editors

Overview

Woman's Urinary System Man's Urinary System

When you cannot empty your bladder completely, or at all, despite an urge to urinate, you have urinary retention. To understand how urinary retention occurs, it is important to understand the basics of how urine is stored in and released from the body.

The bladder is a balloon-like organ in the lower part of the belly (pelvis) that stores urine.

  • Urine is composed of waste and water filtered from the blood by the kidneys.
  • It travels down two thin tubes called ureters (one from each kidney) to the bladder.
  • When about 1 cup (200 ml-300 ml) of urine has collected in the bladder, a signal is produced in response to the stretch of the bladder from the nerves located in the bladder wall. This signal is sent to the nerves in the spinal cord and the brain, and the brain then returns a signal that starts contractions in the bladder wall. At the same time, another signal is sent to the internal sphincter muscle to relax.
  • These two reactions combined allow urine to flow out of the bladder and down a narrow tube called the urethra.
  • From there, it is released from the body by urination (or micturition).
  • To a certain point, urination can be voluntarily controlled. We are all familiar with the experience of having to urinate at an inconvenient time. When you "hold it in," you are squeezing a muscle called the external sphincter to keep urine in the urethra.

Urinary retention can be an acute (new, short-term) or chronic (ongoing, long-term) condition. It routinely requires medical attention, sometimes hospitalization, for treatment, symptom relief, and detection of the underlying cause. Failure to treat the condition can lead to infections or damage to the urinary tract and kidneys.

Urinary retention is not an unusual condition, and it is more common in men than in women.

Causes

The two essential causes of urinary retention are (1) blockage of the urethra and (2) disruption of the delicate and complex system of nerves that connects the urinary tract with the brain and the nervous system (as described earlier).

Common causes

Blockage (obstruction):
The most common cause of blockage of the urethra in men is enlargement of the prostate. In males, the prostate gland partially surrounds the urethra. If the prostate becomes enlarged, which is common in older men, it presses on the urethra and can block it. The most common cause of prostate enlargement is benign prostatic hypertrophy (often called BPH). Other causes of prostate enlargement include prostate cancer and prostate infection (prostatitis). Causes of blockage of the urethra that can occur in both sexes include scar tissue, injury (as in a car wreck or bad fall), blood clots, infection, tumors in the pelvic region, and stones (rare).
Nerve problems:
Disruption of the nerves between the bladder and the brain can cause you to lose control of your bladder function. The problem may lie in the nerves that send messages back and forth or in the nerves that control the muscles used in urination, or both. Some forms of this condition are referred to as neurogenic bladder. Occasionally, urinary retention is the first sign of spinal cord compression, a medical emergency that must be treated right away to prevent permanent, serious disability. The most common causes of this disruption include spinal cord injury, spinal cord tumor, strokes, diabetes mellitus, herniated or ruptured disk in the vertebral column of the back, or an infection or blood clot that places pressure on your spinal cord.
Infection:
An infection in the pelvic area, such as herpes, can interfere with nerves in the area. Inflammation and swelling caused by infections can also compress the urethra. Infections around the spinal cord can cause retention by placing pressure on the nerves of the spinal cord.
Surgery:
Urinary retention is a relatively common problem after surgery. It can be a direct result of the anesthetic or the type of operation. Relative immobility after a surgery can also contribute to urinary retention. Previous bladder or prostate surgeries can sometimes cause urinary retention because of the formation of strictures (narrowing) due to scar tissue.

Medication-related causes

Certain medications can cause urinary retention, especially in men with prostate enlargement. Many of these medications are found in over-the-counter cold and allergy preparations.

  • Drugs that act to tighten the urinary channel and block the flow of urine include ephedrine (Kondon's Nasal, Pretz-D), pseudoephedrine (Actifed, Afrin, Drixoral, Sudafed, Triaminic), and phenylpropanolamine (Acutrim, Dexatrim, Phenoxine, Prolamine).
  • Antihistamines such as diphenhydramine (Benadryl, Compoz, Nytol, Sominex) and chlorpheniramine (Chlor-Trimeton, Allergy 8 Hr), as well as some older antidepressants, can relax the bladder too much and cause urination problems.

Urinary retention in children

  • A child can have problems from birth that cause an inability to urinate properly. These problems usually become apparent within the first six months of life.
  • A child may suddenly become unwilling to urinate. This is generally due to a temporary condition, causing them pain with urination. Pain can be caused by a vaginal yeast infection in girls or an irritation from soap or shampoo used in bathing. Almost always, the child will eventually urinate without further help.

Other causes

Chronic urinary retention usually develops slowly because the bladder does not empty completely. It may take a very long time to be diagnosed because you may not have any symptoms.

  • A weak bladder muscle, chronic obstruction, and nerve diseases or injury all can contribute to chronic urinary retention.
  • Chronic retention can lead to urinary incontinence (the unwanted leakage of urine from the bladder), urinary tract infection, and kidney failure.
  • Prolonged immobility can increase the risk of urinary retention.

Symptoms

With urinary retention, there is an inability to empty the bladder despite an urge to urinate. Some people have the following symptoms:

  • Most people with acute urinary retention also feel pain in the lower abdomen (pelvis) along with inability to urinate. Chronic urinary retention is usually painless because some amount of urine is able to get out of the bladder. This can become painful with the absence of urination or if the amount of retained urine increases.
  • A small amount of urine may leak out of the bladder but generally not enough to relieve symptoms.
  • With chronic urinary retention or sensory problems, there may be no symptoms.
  • Back pain, fever, and painful urination may indicate a urinary tract infection.

When to Seek Medical Care

Call your health-care provider immediately if you have symptoms of acute urinary retention.

  • This condition requires urgent bladder drainage to prevent damage to the bladder, kidneys, and ureter.
  • Your doctor may advise you to go to a hospital emergency department without delay.
  • Urologists (doctors specialized in the urinary tract system) are most often involved in the care of patients with urinary retention. Internists, family physicians, and emergency-room physicians also frequently treat urinary retention.

Exams and Tests

Medical evaluation for urinary retention includes a medical and physical examination (including a prostate examination in men) to find the cause of the problem.

A catheter can be placed in the urethra. This is a thin, flexible tube. It goes up the bladder and drains the urine into a bag.

  • This is done both for diagnosis and as a treatment of the immediate problem. Draining urine almost always relieves the symptoms, at least for a while.
  • A urine sample will be taken to check for signs of infection, bladder irritation, stones, or other problems.

Other lab tests may be done, depending on your doctor's conclusions from your medical interview and exam.

  • Blood may be drawn to check for signs of infection, to check your electrolyte balance, and possibly to rule out certain conditions.
  • The blood also may be checked for prostate-specific antigen (PSA). This is the same test used to screen men for prostate cancer.
  • A sample of the secretions from your penis (men) or vagina (women) may be checked for signs of infection as well.

If the doctor suspects an acute nerve problem causing urinary retention, a CT scan or MRI of the spine can be done for further evaluation.

  • People with chronic urinary retention or suspected bladder muscle weakness may be referred to a specialist in disorders of the urinary tract (urologist).
  • The urologist may perform advanced urodynamic testing to see what is causing the problem.
  • If necessary, an ultrasound may be recommended to examine the upper urinary tract (the kidneys and ureters) to evaluate their size and examine for evidence of infection, stones, or other possible clues regarding the cause of urinary retention.
  • The urologist also may recommend cystoscopy. A cystoscope is a thin, flexible tube with a tiny camera on the end. It is inserted through the urethra to examine the bladder, urethra, and prostate for abnormalities that can cause urinary retention.

Inability to Urinate Treatment

Self-Care at Home

Acute urinary retention requires immediate drainage for relief and thus a visit to your health-care provider or a hospital emergency department. You can try very limited care at home, but do not delay medical evaluation if you are in pain. Try sitting in a bathtub full of warm water or running the water in the bathroom to stimulate the flow of urine.

If a medication is thought to be the cause of urinary retention, your doctor may recommend to discontinue it and monitor for any improvement.

People with limited mobility (for example, after a medical illness or a surgery with prolonged recovery period) resulting in inability to urinate can be encouraged to get up and walk, as this increased activity may facilitate urination.

Medical Treatment

If urinary retention is thought to be acute, severe, or painful, a Foley catheter may be inserted through the urethra into the bladder. This is a small, flexible rubber or silicone tube. Once it has reached the bladder, urine will drain out into a bag.

  • The catheter can either be removed immediately or kept in place to provide continuous drainage.
  • The decision to remove the catheter will depend on the amount of urine obtained, the cause, and the likelihood that your symptoms will come back.
  • The normal bladder capacity in adults is about a cup and a half (13.5 oz or 400 ml). If much more urine than this is retained, the catheter may be left in place to allow the bladder to contract to its normal size.
  • Sometimes when the retained urine is finally drained, it is bloody or slightly pinkish. This is usually minor and stops on its own in a short time. Your physician will monitor this to make sure it stops.

If a catheter cannot reach your bladder because of an obstruction in the urethra, an alternative procedure can be tried.

  • The most common reason for the obstruction is a narrowing or stricture within the urethra.
  • The catheter can be placed through your skin, over your pubic bone, and through the lower abdominal wall directly into your bladder. This is called the suprapubic route. This procedure is generally performed by urologists. The tube will provide temporary drainage until the situation can be managed via a cystoscopic procedure.
  • Various dilators may be used to open the urethral channel wide enough to pass a catheter through.
  • A urologist may do an immediate cystoscopy to insert the catheter under direct vision.

In the last few years, devices have become available that can help some people with chronic urinary retention. For example, an implantable device is available that stimulates the nerves that control the bladder. In some people, this helps the bladder relax and contract at the right times to allow urination.

Next Steps

Medications

Two types of medications available for treating enlarged prostate in men are also generally used in the treatment of urinary retention.

The first class of medications (called alpha receptor blockers) work by relaxing the muscles at the neck of the bladder, thus reducing the obstruction to the flow of urine. The common medications in this class are terazosin (Hytrin), tamsulosin (Flomax), doxazosin (Cardura), and alfuzosin (Uroxatral). These medications are generally used for treating long-standing obstructive symptoms due to enlarged prostate, but they may have a role in treating acute obstruction. Some studies have suggested that early initiation of these medications may improve urinary problems upon the removal of a urinary catheter.

The second class of medications for the treatment of prostate enlargement (called 5-alpha reductase inhibitors) work by shrinking the size of the prostate gland. They inhibit locally (in the prostate) the conversion of testosterone to one of its metabolites which is thought to play a role in increasing prostate size. Finasteride (Proscar) and dutasteride (Avodart) are the two commonly used medications of this type. They are also primarily used to treat long-standing urinary problems due to prostate enlargement. Unlike the other drug class, they play no role in treating acute urinary obstruction because their action of reducing the prostate size may take weeks to months.

Follow-up

When a catheter is left in place after the initial treatment, a visit to a medical professional, usually a urologist, within a few days is generally recommended.

  • Sometimes, antibiotics may be necessary to prevent infections. Catheters are a common cause of urinary tract infections and need routine care. If catheters are necessary for long-term treatment, it is advisable to change them on a regular schedule (typically every three to four weeks).
  • Either of two types of drainage bags can be hooked up to the catheter. A smaller bag can be strapped to the leg (called a leg bag), allowing normal activity without anyone knowing that a catheter is in place. A larger bag may be used at night to prevent waking up at night to empty it. This larger bag is the one typically seen in hospitalized patients hanging by the bedside.
  • Contact your doctor if the catheter stops draining. It is possible that a blood clot, tissue, or debris can plug the catheter. Symptoms of urinary retention can potentially come back and there may be leakage of urine around the catheter. In these situations, the catheter will often require irrigation or replacement.

People with a Foley catheter may experience bladder spasms. The catheter is held in the bladder by a balloon at its tip that is inflated with sterile water after the insertion of the catheter. Sometimes, the bladder will contract to try to expel the balloon.

  • These spasms can be painful and can result in the leakage of urine from around the catheter. Medication is available to treat these symptoms if necessary.

Catheter removal is a simple procedure that can be performed in any medical office.

  • It is best done in the morning, if possible. This allows for the entire day to resume normal urination.
  • If urinary retention continues, the catheter can be replaced later in the day.

Prevention

Good urination habits are essential to keep the bladder functioning normally. Most people normally urinate four to six times per day. Frequent holding of urination for prolonged periods can weaken bladder muscles because of overstretching. This may not seem like a problem initially, but over the course of 20-30 years, it can cause urination problems.

Outlook

The prognosis depends on the source of the problem.

  • People with urinary retention caused by obstruction, infection, drugs, or the postoperative state generally recover much more easily than those with a nerve problem. The time frame for recovery varies, however.
  • People who continue to have urinary retention despite treatment may need long-term therapy. The best option for long-term therapy is clean, intermittent catheterization.
  • You or your caregiver can be taught how to insert a removable catheter into the bladder to allow urine to drain.
  • Catheterization can either be a temporary measure until normal urination returns or be more permanent.
  • The other option is placing a Foley catheter into the bladder either via the urethra or through the skin. Tubes will be changed monthly to limit the risk of infection.
  • Clean, intermittent catheterization also remains a treatment option for people who can urinate but cannot completely empty the bladder.
  • Sometimes, by teaching a person to self-catheterize one to three times per day, the problem can be improved significantly.

Authors and Editors

See http://www.emedicinehealth.com/inability_to_urinate/page13_em.htm