Prostatic enlargement invariably presents itself through urinary symptoms. The relationship between the prostate and the bladder is that of close anatomical kinship. The prostate gland is located immediately below the bladder at the bladder apex. The tube which carries the urine out of the bladder, known as the urethra, passes through the prostate as it exits the bladder. Therefore, prostatic disease can be regarded partially as a bladder problem.
The initial symptoms of enlargement of the prostate occur because of the pressure the enlarging prostate exerts on the urethra and the bladder. Patients experience difficulty passing urine because the urethra is compressed. The urine stream becomes weaker and urination, which was once an effortless daily occurrence, becomes a burden on the patient. Many men at this point suspect that their urinary difficulties are due to a bladder problem, seldom do they suspect that the enlarging prostate is behind it all.
As the condition progresses and the size of the prostate gland increases, the bladder undergoes various changes in order to accommodate the increasing pressure applied at its apex by the larger than average prostate. This bladder problem is a condition identified by the medical community as “bladder outlet obstruction”.
The bladder initially becomes over distended with urine and never empties completely, and then the bladder refills faster with urine. This is turn results in a shortened interval between trips to the toilet, which manifests itself as a bladder problem known as frequency. The bladder wall thickens resulting in bladder hypertrophy, increasing the weight of the urinary bladder.
The bladder muscle hypertrophy, which follows the enlargement of the prostate gland, does not develop overnight. It is a gradually progressive condition which, at first, causes no or very few symptoms but then leads to the development of a major bladder problem, the overactive bladder syndrome.
An overactive bladder, also referred to as an irritable bladder, is the underlying cause of urinary urgency and urge incontinence in males with prostate disease. The irritable bladder syndrome occurs because of the hyperactivity of the bladder muscle wall (the detrusor muscle). Approximately 80% of all men with benign prostatic enlargement suffer from detrusor instability. The patients suffer from uncontrollable contractions of the hypersensitive detrusor muscle leading to a variety of urinary symptoms including urgency, frequency and even urinary incontinence.
The detrusor muscle, the muscle of the bladder wall, although hypertrophied and thickened by the chronic bladder obstruction, is also weakened by the excessive and chronic stretching of its fibres. This makes it unable to contract properly and empty the bladder fully. This condition increases the risk of urinary tract infections especially of predisposed patients such as those with diabetes or who are immune compromised. This weakness of detrusor muscle is also one of the underlying causes for the male bladder problem of urinary dribbling after voiding is completed.
While enlargement of the prostate cannot be simply reduced into a bladder problem, the bladder most definitely remains the organ that suffers the most when the prostate gland increases drastically in size.