The symptoms commonly associated with BPH are collectively called lower urinary tract symptoms (LUTS). BPH is not always the cause of these symptoms. An enlarged prostate may be accompanied by few symptoms, while severe LUTS may be present with normal or even small prostates and are most likely due to other conditions. Many experts are now categorizing LUTS as either voiding or storage symptoms to help define the source of the problem.
Voiding (Obstructive) Symptoms
Voiding symptoms, also referred to as obstructive symptoms, can be caused by an obstruction in the urinary tract. They are often due to BPH. Obstruction is the most serious complication of BPH and requires medical attention. Voiding symptoms include:
- Weak or intermittent urinary stream
- Straining when urinating
- A hesitation before urine flow starts
- A sense that the bladder has not emptied completely
- Dribbling at the end of urination or leakage afterward
Storage (Irritative) Symptoms
Storage symptoms, also referred to as irritative symptoms, include:
- An increased frequency of urination, particularly at night
- An urgent need to urinate
- Bladder pain or irritation when urinating
Urine flows from the kidney through the ureters into the urinary bladder where it is temporarily stored. As the bladder becomes distended with urine, nerve impulses from the bladder signal the brain that it is full, giving the individual the urge to void. By voluntarily relaxing the sphincter muscle around the urethra, the bladder can be emptied of urine. Urine then flows out through the urethra.
Serious Symptoms
More serious symptoms may include:
- Blood in the urine
- Recurrent urinary tract infection
- Back-up of urine into the kidneys
- Acute urinary retention (inability to void)
The causes of benign prostatic hyperplasia are not fully known. Several theories have been proposed to explain benign cell growth in older men.
Hormonal Changes
Male Hormones. Androgens (male hormones) most likely play a role in prostate growth. The most important androgen is testosterone, which is produced throughout a man's lifetime. The prostate converts testosterone to a more powerful androgen, dihydrotestosterone (DHT). DHT stimulates cell growth in the tissue that lines the prostate gland (the glandular epithelium) and is the major cause of the rapid prostate enlargement that occurs between puberty and young adulthood. DHT is a prime suspect in prostate enlargement in later adulthood.
Estrogen. Some authorities believe that the female hormone estrogen may also play a role in BPH. (Some estrogen is always present in men.) As men age, testosterone levels drop, and the proportion of estrogen increases, possibly triggering prostate growth.
Late Activation of Cell Growth
Another theory focuses on cells in a certain section of the gland that may become active late in life, signaling other prostate cells to replicate or causing them to be sensitive to growth-stimulating hormones.
Defective Cell Death
This theory suggests that a process known as apoptosis, in which cells naturally self-destruct, goes awry and results in cell proliferation.
Blood Vessel Injury
Some experts theorize that the blood vessels in the prostate gland may deteriorate as men age, causing abnormal blood flow and oxygen loss, which would stimulate cell growth. Such a theory is supported by the presence of heart and circulatory problems in many men with BPH.
