Benign Prostatic Hyperplasia
Benign prostatic hyperplasia (BPH) is not simply a case of too many prostate
cells. Prostate growth involves hormones, occurs in different types of tissue
(e.g., muscular, glandular), and affects men differently. As a result of these
differences, treatment varies in each case. There is no cure for BPH and once
prostate growth starts, it often continues, unless medical therapy is started.
The prostate grows in two different ways. In one type of growth, cells
multiply around the urethra and squeeze it, much like you can squeeze a straw.
The second type of growth is middle-lobe prostate growth in which cells grow
into the urethra and the bladder outlet area. This type of growth typically
The prostate is a walnut-sized gland located beneath the bladder and in front
of the rectum. It is surrounded by a capsule of fibrous tissue called the
prostate capsule. The urethra (tube that transports urine and sperm out of the
body) passes through the prostate to the bladder neck. Prostate tissue produces
prostate specific antigen and prostatic acid phosphatase, an enzyme found in
seminal fluid (the milky substance that combines with sperm to form semen).
Incidence and Prevalence
It is difficult to establish incidence and prevalence of BPH because research
groups often use different criteria to define the condition. According to the
National Institutes of Health (NIH), BPH affects more than 50% of men over age
60 and as many as 90% of men over the age of 70.
BPH is a condition of aging. Nearly all men over the age of 50 have an
The cause of benign prostatic hyperplasia is unknown. It is possible that the
condition is associated with hormonal changes that occur as men age. The
testes produce the hormone testosterone, which is converted to
dihydrotestosterone (DHT) and estradiol (estrogen) in certain tissues. High
levels of dihydrotestosterone, a testosterone derivative involved in prostate
growth, may accumulate and cause hyperplasia. How and why levels of DHT increase
remains a subject of research.
Signs and Symptoms
Common symptoms of benign prostatic hyperplasia include the following:
- Blood in the urine (i.e., hematuria), caused by straining to void
- Dribbling after voiding
- Feeling that the bladder has not emptied completely after urination
- Frequent urination, particularly at night (i.e., nocturia)
- Hesitant, interrupted, or weak urine stream caused by decreased force
- Leakage of urine (i.e., overflow incontinence)
- Pushing or straining to begin urination
- Recurrent, sudden, urgent need to urinate
In severe cases of BPH, another symptom, acute urinary retention (the
inability to urinate), can result from holding urine for a long time, alcohol
consumption, long period of inactivity, cold temperatures, allergy or cold
medications containing decongestants or antihistamines, and some prescription
drugs (e.g., ipratropium bromide, albuterol, epinephrine). Any of these factors
can prevent the urinary sphincter from relaxing and allowing urine to flow out
of the bladder. Acute urinary retention causes severe pain and discomfort.
Catheterization may be necessary to drain urine from the bladder and obtain