Those with urinary retention suffer from the inability to empty their bladder completely. While they can usually still go to the bathroom, they often feel they have retained urine despite excreting as much as they could.
Acute urinary retention happens suddenly and lasts only a short time. Chronic urinary retention, on the other hand, can be long-lasting and is likely caused by a medical condition. Acute variants can be potentially life-threatening, causing great discomfort or pain and requiring immediate medical treatment. Chronic variants of the condition permit a small amount of urine output, leading sufferers to feel they have not completely emptied their bladders.
Urinary retention is more common in men than women. Men 40- to 83-years old have an overall incidence of 4.5–6.8 per 1000 men. This incidence increases as men get older, with men of age 70 or older having an increased chance of developing the disorder (100–300 per 1000 men). It is believed that this correlation is related to the prostate.
How is urinary retention caused?
Obstruction of the urethra
Blockage of any sort in the urethra can prevent normal urine output.
- Benign prostatic hyperplasia – Commonly develops in men in their 50s and 60s and is due to the enlargement of the prostate gland. This condition is not cancerous. The prostate is part of a male’s reproductive system and surrounds the urethra at the neck of the bladder. Because of this anatomical position, it can easily restrict urine flow as the prostate enlarges.
- Urethral stricture – A narrowing or closure of the urethra. It can be caused by inflammation and scar tissue from surgery, prostatitis, scarring after an injury to the penis or perineum (the area between the anus and the sex organs) or surgery for benign prostatic hyperplasia and prostate cancer.
- Urinary tract stones – These form from the development of crystals that form in the urine, building up on the inner surfaces of the kidneys, ureters, or bladder. Once a stone has formed, it has the ability to travel downstream to any site in the urinary tract, leading to obstruction.
- Cystocele – Bulging of the bladder into the vagina. This condition occurs when the muscles and supportive tissues between a woman’s bladder and vagina weaken and stretch. This abnormal position can press and pinch the urethra.
- Rectocele – A bulging of the rectum into the vagina. Occur for a similar reason as a cystocele but is due to the weakening of muscles and supportive tissues between the rectum and vagina.
- Constipation – Having fewer than three bowel movements a week, leading to hard stools that are dry and difficult to pass, causing feelings of bloating or distention of the abdomen. Having hard stools in the intestinal tract can push against the bladder and urethra, leading it to become pinched.
- Tumors and cancers – Having uncontrolled cell growth can gradually expand and obstruct urine flow.
The muscles that control the bladder and various sphincters can be compromised by problems with the nerves. Normally, a signal is sent from the brain down the spinal cord and it ends at their destination where a muscle contraction occurs, and in the cases of the bladder, allows for urine to be expelled. If there is a problem with this chain, either at the level of the brain or at any nerve or nerve junction, it can lead to the inability for the bladder to push urine out. Damaged nerves may also prevent the bladder from relaxing, limiting the amount of urine that can fill it up. Common causes of nerve problems include stroke, multiple sclerosis, and brain or spinal cord infections.
Various prescription and over-the-counter medication can cause urinary retention by interfering with nerve signals to the prostate and/or bladder. Common drug classes that can cause this includes antihistamines, anticholinergics, tricyclic antidepressants, and various other medications involved in decongestion, pain relief, and preventing seizures.
Weakened bladder muscles
As we age, the muscles of the bladder progressively become weaker. This presents an issue for completely emptying the bladder, resulting in urinary retention.
Symptoms of urinary retention
The symptoms of acute urinary retention include the following and require immediate medical attention:
- Inability to urinate
- Painful, urgent need to urinate
- Pain or discomfort in the lower abdomen
- Bloating/distension of the lower abdomen
Chronic cases of urinary retention may go unnoticed for quite some time. This is often due to its symptoms not immediately being recognized by the patient. The symptoms of chronic urinary retention may include:
- Urinary frequency—urinating about eight or more times a day
- Trouble beginning a urine stream
- A weak or an interrupted urine stream
- An urgent need to urinate with little success when trying to urinate
- Feeling the need to urinate after finishing urination
- Mild and constant discomfort in the lower abdomen and urinary tract
How to diagnose urinary retention
The cause of the retention will dictate how it is diagnosed. However, there are there are various criteria that are used in both scenarios.
First will be the physical exam. Your doctor will try to assess the reasons you may be experiencing urinary obstruction related symptoms such as abdominal pain and distention. Once the diagnosis has been isolated to the region of the urinary tract, a post void residual measurement will be obtained.
A postvoid residual measurement test measures the amount of urine left in the bladder after urination. It is done by a specially trained technician that performs a bladder ultrasound in a health care provider’s office. This procedure can be done without anesthesia.
The following are additional tests that can be ordered to get more data on urinary obstruction:
Cystoscopy: A tube-like instrument called a cystoscope is used to look inside the bladder. Local anesthesia is often used and can be done as an outpatient. This may aid in the diagnosis of urethral structures.
CT scans: Able to give a detailed look at all urinary tract structures. It can be done as an outpatient procedure by a radiologist. CT scans can help diagnose urinary tract stone, tumors, and abnormal, fluid filled sacs called cysts.
Urodynamic tests: Includes a variety of procedures that look at how well the bladder and urethra store and release urine. These tests may include uroflowmetry, measuring the amount of urine and flow rate; pressure flow studies, measuring bladder pressure required to urinate; and video urodynamics, using x-rays or ultrasound to create real-time images of the bladder during the filling and emptying process of the bladder.
Related: Urinary incontinence types: Stress, urge, overflow, functional, mixed, and transient