Understanding Acute Urinary Retention and Its Management Options

Acute urinary retention (AUR) is a sudden and painful inability to urinate despite having a full bladder. This condition requires immediate medical attention because it can cause severe discomfort and lead to complications if untreated. Understanding what AUR is, how it is managed, and what to expect during treatment can help patients and caregivers navigate this urgent health issue with confidence.

What Is Acute Urinary Retention?

Acute urinary retention occurs when the bladder fills with urine, but the person cannot empty it voluntarily. This blockage can happen suddenly and may be caused by various factors such as an enlarged prostate, urinary tract infections, medications, or nerve problems affecting bladder control.

The inability to urinate causes the bladder to stretch and become painful. If not relieved quickly, this pressure can damage the bladder and kidneys. Because of this, AUR is considered a medical emergency.

How Is Acute Urinary Retention Treated?

The immediate treatment for AUR is to relieve the pressure by draining the bladder. This is done by inserting a thin, flexible tube called a catheter through the urethra into the bladder. The catheter allows urine to flow out freely, easing the pain and preventing damage.

Example of an inflated catheter

The catheter is usually temporary. Once the bladder is empty and the underlying cause is addressed, doctors plan a voiding trial to check if the patient can urinate normally without the catheter.

What Is a Voiding Trial?

A voiding trial, also known as a trial without a catheter, tests whether the bladder can empty on its own after the catheter is removed. During this trial, the catheter is removed, and the patient is given up to six hours to urinate naturally.

Medical staff monitor the patient closely during this time. If the patient can urinate successfully, the catheter is not needed anymore. If the patient cannot urinate, the catheter may be reinserted, and another trial will be scheduled later.

Understanding Bacteria and Catheter Use

When a catheter is in place, bacteria often grow in the bladder. This is called bacterial colonization and happens to nearly everyone with a catheter. The risk of bacteria appearing in the urine increases the longer the catheter stays in:

• Each day with a catheter adds about a 3% to 8% chance of bacteria growing in the urine.

• After 3 days, about 15% of patients have bacteria in their urine.

• After 8 days, this rises to approximately 68%.

• If the catheter remains for a long time, nearly all patients will have bacteria present.

  
  

Most of the time, these bacteria do not cause symptoms or illness. This condition is called asymptomatic bacteriuria—bacteria are present, but there is no infection. When there are no symptoms, antibiotics are usually not needed because unnecessary use can promote antibiotic resistance.

Why Bacteria Matter During a Voiding Trial

While bacteria in the urine usually do not cause problems when the catheter drains urine freely, the situation can change during a voiding trial. If the patient cannot urinate after catheter removal, urine may remain in the bladder, increasing the risk of infection.

A failed voiding trial means the bladder is not emptying properly, which can allow bacteria to multiply and cause symptoms such as burning, urgency, or fever. In such cases, medical teams may need to treat infections or adjust the management plan.

What Your Doctor Will Do to Protect You

To lower the risk of infection and improve your chances of urinating on your own, your doctor may take the following steps:

1. Obtain a urine culture before the voiding trial.

A urine sample will be collected from your catheter and sent to the laboratory. This test identifies exactly which bacteria (if any) are present in your bladder and which antibiotics will work against them. The results help your doctor choose the right antibiotic to protect you.

2. Give you an antibiotic just before the voiding trial.

Based on the urine culture results, your doctor may give you a dose of the appropriate antibiotic shortly before the catheter is removed. Research has shown that antibiotic prophylaxis at the time of catheter removal can reduce the risk of developing a symptomatic UTI by approximately 50% or more. This is especially important for patients who:

• Are older than 60 years

• Have had the catheter in place for more than 5 days

• Are at higher risk of not being able to urinate (failed voiding trial)

3. Prescribe or adjust an alpha-blocker medication.

Your doctor will likely prescribe a medication such as tamsulosin (Flomax) or alfuzosin. These medications relax the muscles around the bladder and prostate, making it easier to urinate. Taking this medication as directed can nearly double your chance of urinating successfully when the catheter is removed.

If you are already taking tamsulosin (Flomax) for an enlarged prostate, your doctor may temporarily increase your dose — for example, from one capsule (0.4 mg) to two capsules (0.8 mg) per day — to give you the best possible chance of urinating on your own during the voiding trial. The higher dose provides stronger relaxation of the prostate and bladder neck muscles. Do not change your dose on your own — only take the dose your doctor prescribes, as the higher dose can sometimes cause dizziness or lightheadedness, especially when standing up quickly.

4. Add a prostate-shrinking medication (for patients already on an alpha-blocker).

If you have been taking an alpha-blocker such as tamsulosin (Flomax) for an enlarged prostate and you still developed urinary retention, your doctor may add a second type of medication called a 5-alpha reductase inhibitor — such as finasteride (Proscar) or dutasteride (Avodart).

Here is what you should know about these medications:

How they work: While alpha-blockers relax the muscles around the prostate, finasteride and dutasteride actually shrink the prostate itself by about 20–25% over time. A smaller prostate means less blockage and a lower chance of urinary retention happening again.

They take time to work: These medications work gradually. It typically takes 3 to 6 months before the prostate shrinks enough to make a noticeable difference. This means they will not help with your first voiding trial, but they are very important for your long-term health.

They significantly reduce your risk of future problems: Large clinical studies have shown that adding finasteride or dutasteride to an alpha-blocker can:

• Reduce the risk of urinary retention happening again by approximately 68%

• Reduce the chance of needing prostate surgery by approximately 70%

• Provide much better long-term protection than an alpha-blocker alone

Why starting now matters: Even though these medications take months to reach full effect, starting them now — while you are recovering from this episode — means they will be working to protect you in the months ahead. Research shows that alpha-blockers alone do not reduce the long-term risk of retention or surgery, but adding a prostate-shrinking medication does.

Possible side effects: These medications can cause decreased sex drive, difficulty with erections, or decreased ejaculation in some men (roughly 4–8 out of 100). Breast tenderness or enlargement can also occur rarely. These side effects often improve over time and are reversible if the medication is stopped. Discuss any concerns with your doctor.

How to Improve Your Chances of a Successful Voiding Trial

Take all prescribed medications exactly as directed — the alpha-blocker, any antibiotic, and the prostate-shrinking medication if prescribed.

Treat constipation before your voiding trial. A full bowel puts pressure on the bladder and can make it harder to urinate. If you are constipated, tell your doctor or nurse so they can help you have a bowel movement before the catheter is removed. Eat fiber-rich foods (fruits, vegetables, whole grains) and drink enough fluids.

Stay well hydrated. Drink plenty of water and other clear fluids (unless your doctor has restricted your fluid intake).

Avoid medications that can make urinary retention worse. Tell your doctor about ALL medications you take, including over-the-counter drugs and supplements. The following types of medications can make it harder to urinate:

• Cold and allergy medicines containing decongestants (pseudoephedrine, phenylephrine) or antihistamines (diphenhydramine/Benadryl)

• Sleep aids (many contain antihistamines)

• Bladder-calming medications (oxybutynin, tolterodine, solifenacin)

• Some pain medications, especially opioids (codeine, oxycodone, morphine)

• Certain antidepressants and antipsychotic medications

• Some muscle relaxants

Do NOT stop any prescribed medication without talking to your doctor first — but do let them know everything you are taking.

Limit alcohol. Alcohol can irritate the bladder and worsen urinary problems.

Stay as active as possible. Light walking and movement (as allowed by your medical team) can help your bladder and bowels function better.

Try to relax during the voiding trial. Anxiety and tension can make it harder to urinate. When the catheter is removed, sit comfortably on the toilet, take slow deep breaths, and give yourself time. Running warm water or placing a warm cloth on your lower abdomen may help.

Caring for Your Catheter to Prevent Infection

While you have a catheter, follow these steps to lower your risk of infection:

• Wash your hands with soap and water before and after touching the catheter or drainage bag.

• Keep the drainage bag below the level of your bladder at all times — never raise it above your waist.

• Do not pull or tug on the catheter. Make sure the tubing is secured to your leg and is not kinked or twisted.

• Keep the catheter and the area where it enters your body clean. Gently wash the area around the catheter with soap and water daily. Do not use powders or lotions near the catheter site.

• Do not disconnect the catheter from the drainage bag. Keeping the system closed and sealed is one of the most important ways to prevent infection.

• Empty the drainage bag regularly — do not let it get completely full. Wash your hands before and after emptying it, and do not let the drain spout touch the collection container or the floor.

Warning Signs — When to Seek Help Immediately

Contact your doctor or go to the emergency room right away if you experience any of the following:

• Fever (temperature 100.4°F / 38°C or higher), chills, or shaking

• Cloudy, foul-smelling, or bloody urine

• Pain or burning around the catheter site that is getting worse

• Pain in your lower back or side (flank pain)

• Sudden confusion or unusual drowsiness (especially in older adults)

• No urine draining into the bag for several hours

• Urine leaking around the catheter

• Nausea, vomiting, or feeling very unwell

After catheter removal, seek emergency care if you experience:

• Sudden inability to urinate again

• Severe pain in the lower abdomen

• Heavy bleeding from the urethra (where the catheter was)

• Fever or chills