How does prostate enlargement lead to difficulty starting urination?
Prostate enlargement, or benign prostatic hyperplasia (BPH), can lead to difficulty starting to urinate, known as urinary hesitancy, due to the manner in which the enlarged prostate compresses the urethra and changes bladder function. Here’s why it occurs:
1. Compression of the Urethra
The urethra is the pipe that urine passes through from the bladder out to the body. The prostate surrounds the urethra. When the prostate enlarges, it pushes against and compresses the urethra.
This compression decreases the amount of space the urine flows through, so there is some blockage that increases the resistance to urine flow. When the individual attempts to urinate, the blockage may prevent urine from flowing freely and is hard to start the urine flow.
2. Increased Resistance to Urine Flow
As prostate size increases, the smooth muscle lining of the urethra can become progressively tenser and further decrease the diameter of the urethra.
This increased resistance to the flow of urine causes the bladder to exert greater pressure to overcome it. This may cause difficulties in starting to urinate since the bladder will struggle to push urine past the obstructed point.
3. Bladder Muscle Overactivity
The bladder has muscles (the detrusor muscle) that contract to push out the urine. As a result of the obstruction caused by prostate enlargement, the bladder may be overactive and try to contract hard in an attempt to push urine through the narrowed urethra.
However, even with all these factors, the bladder may not be able to exert enough power to overcome the resistance created by the inflamed prostate. This leads to the difficulty in urinating when one starts to do so, and the person may feel that he cannot initiate the process even with a full bladder.
4. Involuntary Contractions of the Bladder
Because the prostate squeezes the urethra, it can also interfere with the normal sensory feedback between the bladder and the brain. This can lead to abnormal contractions of the bladder muscles that can make it difficult for the person to voluntarily be able to control or initiate urination. This sensation can cause urgency or delay in the flow of urination.
5. Incomplete Relaxation of the External Urethral Sphincter
The external urethral sphincter is the muscle that controls the flow of urine out of the bladder. It must relax so that urination can occur. With prostate enlargement, the increased pressure on the urethra may disrupt the usual relaxation of the sphincter muscle, and it is more difficult to get the urine flowing.
This may lead to hesitancy, where the man has trouble starting urination although he wants to.
6. Urinary Retention
As the prostate enlarges, it may also cause urinary retention, when the bladder is not able to fully empty. This makes it increasingly harder for the patient to start urination since the bladder is constantly strained from retaining excess urine that otherwise it would not retain.
The sensation of having a full bladder and not being able to start urination can form a vicious cycle for patients with BPH.
7. Neurological Effects
The nerves that control the bladder and urethra can indirectly be influenced by prostate enlargement. This could lead to slowed nerve impulses, which consequentially leads to a time lag in the brain’s response to the feeling of having the need to urinate and is one such reason for hesitancy.
Summary:
Prostate enlargement leads to the failure to start urinating due to compression of the urethra, increased resistance to urine flow, and possible bladder overactivity. The enlarged prostate causes blockage in the free flow of urine by narrowing the urethra, thus it becomes difficult for the bladder to initiate urination. The bladder may also become hyperactive, and the external sphincter does not relax totally, which also contributes to urinary hesitancy. All these causes together make it difficult for men with prostate enlargement to initiate urination freely.
Incomplete bladder emptying due to BPH occurs when the enlarged prostate presses against the urethra, making it difficult to fully empty the bladder. This may cause a variety of symptoms that can affect urination. Some common symptoms of incomplete bladder emptying due to BPH are:
1. Straining to Urinate:
An individual may have to strain or push to start urination, as the enlarged prostate obstructs the flow of urine.
2. Incomplete Emptying Feeling:
After urination, one may feel that the bladder is not fully emptied, even if the individual has just urinated. This feeling may lead to the urge to urinate again shortly after completion.
3. Frequent Urination:
Since the bladder is not fully emptied each time, there may be a more frequent need to urinate. This includes more frequent urination during the day or at night (nocturia).
4. Weak or Intermitent Urine Flow:
The urine may start weak or slow, and periodically stop and start while urinating, since the bladder is having trouble releasing due to the obstruction caused by the enlarged prostate.
5. Dribbling After Urination:
There can be dribbling of urine after urination in a few men, as there is leakage of urine in small amounts after they have finished urinating. This is because the bladder is not completely emptied.
6. Urinary Urgency:
There can be a sudden, urgent feeling to urinate, even after recently finishing urination, because the bladder is not emptied properly.
7. Increased Risk for Urinary Retention:
In severe cases, incomplete emptying of the bladder can lead to urinary retention, where the bladder does not fully empty. This can lead to pain, discomfort, and the need for medical intervention.
8. Urinary Tract Infections (UTIs):
If the bladder is not fully emptied, it may encourage urinary tract infections (UTIs), since residual urine in the bladder can provide a conducive environment for bacteria.
9. Pain or Discomfort:
Some men experience discomfort or feeling of pressure in the pelvic region or lower abdomen, especially when they attempt to urinate.
If you experience any of these symptoms, it is important to consult a healthcare provider. They can assess the severity of the symptoms and determine appropriate treatment modalities for managing BPH and preventing complications like urinary retention or infection.