TWO. Benign Prostatic Hyperplasia (BPH)
What causes BPH?
The short answer is that no one knows for sure. The growth of the prostate gland is a complex process that starts at puberty and continues throughout adult life. As a man ages, his prostate grows, although the rate of growth and size of the prostate varies from individual to individual. It is certain that prostate growth, whether it is benign or malignant, requires testosterone and a derivative of testosterone, dihydrotestosterone. Centuries ago, it was observed that the castrati, the Italian opera singers who were castrated at puberty to preserve their tenor voices, never developed enlargement of their prostates.
How common is BPH?
BPH is the most common disease of mankind. It has been said that if a man lives long enough, he will develop BPH; however, autopsy studies have shown that some men, even in their 30s, have anatomic evidence for significant prostate enlargement. The degree of prostatic enlargement is variable; however, the following numbers are useful guidelines. At the age of 30 years, an average prostate size is 20 grams; by age 70 years, the average prostate size is 35 grams.
As an estimate, if you take a man's chronologic age in years, roughly that percentage of men at that age will have signs of BPH. It is important to note that there is not a linear correlation between prostate size and prostate symptoms. Some men with relatively small glands will have significant symptoms, whereas some men with large glands will have minimal symptoms.
What are the symptoms of BPH?
An enlarged prostate can cause a variety of symptoms. Some are referred to as obstructive/voiding symptoms and include weak stream, hesitancy of voiding, intermittent stream, a sensation of incomplete bladder emptying, and terminal dribbling. Storage/irritative symptoms include frequent urination, nocturia (getting up at night to urinate), and urgency, the sudden compelling need to urinate that is difficult to defer. These storage symptoms are overactive bladder symptoms.
Other conditions that may be a sign of prostatic enlargement are urinary retention or the inability to void, urinary tract infection, urinary incontinence, and hematuria or blood in the urine.
It is important to acknowledge that bladder dysfunction can either mimic or contribute to some of these symptoms, and the physician must consider these when a diagnosis of prostatic enlargement is made.
How is BPH diagnosed?
Both a physical exam and history are used to diagnose BPH. When necessary, the urologist may use other diagnostic tests to obtain additional information to help make the diagnosis.
If a patient gives a history that includes one or more of the symptoms mentioned in Question 33, the physician will be alerted to consider BPH as part of his differential diagnosis. Also, when the physician performs a digital rectal exam (palpates or feels the prostate with a finger in the rectum), he or she can feel whether the prostate is enlarged. Your doctor may ask you to complete a simple screening tool called the AUA symptom score, although it is not specific for BPH, it allows the doctor to determine the severity of your symptoms and may provide a way of assessing whether or not your symptoms have improved with treatment. This symptom score has been adopted worldwide with the addition of a question pertaining to quality of life and is referred to as the International Prostate Symptom Score (IPSS) (Figure 20).
Finally, if the physician needs additional information before making a diagnosis of BPH, he or she can do additional tests.