How benign prostate enlargement causes urinary symptoms and UTIs

BPH (benign prostatic hyperplasia), also known as prostate enlargement, produces urinary symptoms including a frequent urge to urinate, an inability to fully empty the bladder and difficulty starting to urinate. Alongside these symptoms, having BPH can lead to  urinary tract infections  (UTI). Mr Jeremy Crew, a top urologist, explains these symptoms.

What are the urinary symptoms of BPH?

BPH can through a number of mechanisms obstruct the urethra and cause urinary symptoms. There are two main ways in which it obstructs the urethra:

1. Firstly, there are the static components of obstruction. What this means is that as the prostate increases in size, the lobes grow to exclude the urethra and inhibit free urinary flow.
2. There is a second component, the so-called dynamic components. The prostate is made up of both fibrous and muscular tissue. This muscular tissue can contract and squeeze the urethra, again, inhibiting the flow of urine.

Invariably, in patients with benign prostatic hyperplasia, it is a combination of both of these. What this means is that the inhibition of the free flow of urine will result in a number of symptoms.

These obstructive symptoms include:

• A poor flow with reduced flow rates
• Hesitancy with patients struggling to initiate voiding
• Intermittency, where a patient will void in a stop-start manner.

On top of these obstructive symptoms, there are the so-called filling symptoms. As a prostate enlarges and obstructs the urethra, this has a secondary effect on the bladder. The bladder has to generate higher pressures in order to overcome the obstructing prostate. What happens is the bladder becomes hyperactive and you develop a so-called unstable bladder.

This will manifest itself in a number of symptoms, such as:

• Urinary frequency (going to pass urine more often during the day than one would expect)
• Urinary urgency (when you feel like you want to pass urine and you have to rush to the lavatory for fear of becoming incontinent)
• Nocturia (where a patient would have to get up 2 to 3 times a night and sometimes more to pass urine)

Occasionally, the urinary symptoms can become very severe and a patient can find that they are unable to void. This is called acute urinary retention. In this situation, a patient will need to have a urethral catheter inserted to drain the urine away.

How do you get a UTI?

Urinary tract infections are one very troublesome complication of an obstructing benign prostatic hyperplasia that can cause patients significant symptoms.

There are two main ways in which BPH cause urinary infections:

1. Firstly, the obstructing urine may inhibit the complete emptying of the bladder, such that post-void residual urine is left within the bladder. This urine can become stagnant and undergo secondary and bacterial infection, leading to urinary tract infection with symptoms of cystitis.
2. The second mechanism by which BPH can predispose to UTIs is that to overcome the obstructing prostate, a bladder needs to increase its pressure: the force with which it exerts to pass urine. This increased pressure against an obstructing prostate can force urine into the prostatic ducts. This urine sitting within prostatic ducts can cause a chemical inflammation, which again can predispose to bacterial infection, leading to symptoms of a UTI, such as cystitis and indeed prostatitis.

If you suffer from BPH and are troubled by urinary symptoms of UTIs, make an appointment with an expert to discuss your treatment options.