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Enlarged Prostate (Benign Prostatic Hyperplasia)


Enlarged prostate, or benign prostatic hyperplasia (BPH), is a common occurrence among aging men. Benign means that the enlargement is not caused by cancer or infection. Prostatic refers to the area affected, the prostate gland, and hyperplasia means enlargement. As many as 50% of men experience symptoms of an enlarged prostate by age 60, and 90% of men will report symptoms by age 85. Since symptoms of enlarged prostate tend to worsen over time, it is important for men to understand the symptoms and the options for enlarged prostate treatment.

Enlarged Prostate Background

The prostate gland is located just below the bladder at the site where the bladder connects to the urethra. The urethra is a tube inside the penis that carries urine and semen out of the body. The prostate gland resembles a chestnut in size and shape, and it has an important role in sexual function; it produces semen, which is a transport fluid for sperm.


In most men, the prostate gland will undergo two stages of growth. The first stage occurs early in life and is usually complete by the end of puberty. The prostate usually remains the same size for many years; however, it may begin growing again during middle age, and some men develop symptoms by age 40. If the prostate becomes enlarged it may compress the urethra, which can interfere with elimination of urine and semen. The interference with urine elimination can cause a number of irritating symptoms and can lead to more serious problems as well.


Enlarged Prostate Causes

Physicians are not certain exactly why prostate growth occurs, but it is thought that it may be due to an excess amount of certain hormones in the body. One theory regarding the origin of an enlarged prostate involves a hormone called dihydrotestosterone (DHT). DHT is a natural hormone that is responsible for the initial stages of prostate growth. Persistently elevated DHT levels may cause the prostate to continue growing after it has reached full size. Physicians have noted that men who do not produce DHT do not experience enlarged prostate problems. Research has also shown that estrogen and genetics may play roles in enlarged prostate glands.

The role of estrogen can be explained by changing levels of testosterone. It is known that men produce testosterone and a small amount of estrogen throughout their lives; with aging, the amount of testosterone in the blood decreases, which leaves a larger proportion of estrogen. Studies have shown that higher levels of estrogen have been found in men who have enlarged prostate glands.


Many physicians believe that genetics play a role as well. Men with a family history of enlarged prostate may be at greater risk than others.

It is important to note that there are several factors that determine the severity of the symptoms associated with enlarged prostate: the actual size of the prostate; the portion of the gland that is enlarged; and the degree to which smooth muscle tone in the urethra is increased. Interestingly, the size of the prostate gland does not necessarily predict the severity of the enlarged prostate symptoms. A large gland may not cause any obstruction, and a small gland may cause a lot. However, it is known that very large prostate glands almost always cause significant problems. The portion of the prostate gland that is enlarged can be very significant; for example, enlargement involving the median lobe is more likely to be associated with more severe symptoms. In the case of prostates, just as in real estate, location matters most. Enlarged prostate is frequently associated with increased tone in the smooth muscle of the urethra, and many of the irritative symptoms associated with enlarged prostate are due to this increased muscle tone and the resulting interference with urine flow.


Enlarged Prostate Symptoms

Men may experience varying enlarged prostate symptoms; however, most men experience problems relating to the obstruction of urine flow. Some common symptoms include:


A weak or interrupted urinary stream

Sudden urgency to urinate

More frequent urination

Inability to completely empty the bladder during urination

Trouble initiating urine flow even when bladder feels full

Some men with an enlarged prostate do not experience any of these symptoms. The only way to be certain whether or not you have an enlarged prostate is to consult a physician.


Important note: Symptoms of bladder cancer, overactive bladder (OAB), and urinary retention may be similar to those associated with enlarged prostate. It is important to have your primary care physician make a referral to a urologist if you fall into any of the following categories:


Young patients

Abnormal rectal exam, PSA, or urinalysis (see descriptions of these procedures below)

History of extensive urethral instrumentation or stricture

Poor response to medical therapy

Enlarged Prostate Diagnosis

In order to determine the severity of your symptoms being experienced, you may be evaluated using the Enlarged Prostate Symptom Score Index. This diagnostic system includes a series of questions that ask how often you experience various symptoms associated with an enlarged prostate. Along with this test your physician will most likely conduct a thorough medical history, a complete physical (including a digital rectal exam), and a urinalysis. Depending on your individual case, additional tests may be administered. Some of these tests include: Prostate Specific Antigen (PSA) test, a cytoscopy, and urodynamic testing. A description of each of these tests may be helpful:


Score       0      1      2      3      4      5
During the last month or so, how often had you had a sensation of not emptying your bladder completely after you finished urinating?
During the last month or so, how often have you had to urinate again less than two hours after you finished urinating?
During the last month or so, how often have you found you stopped and started again several times when you urinated?
During the last month or so, how often have you found it difficult to postpone urination?
During the last month or so, how often have you had a weak urinary stream?
During the last month or so, how often have you had to push or strain to urinate?
During the last month or so, how many times did you most typically get up to urinate from the time you went to bed at night until the time you get up in the morning? 

Disease Severity Scores: Mild: 0 to 7 | Moderate: 8 to 19 | Severe: 20 to 35 Adapted from Barry MJ, et al. J Urol. 1992;148:1549-1557. Digital


Rectal Exam: A digital rectal exam is included in the physical examination because it is simple and very effective in detecting an enlarged prostate. Due to the natural position of the prostate gland, an enlargement can usually be felt through the wall of the rectum. Your physician will insert a gloved finger into your rectum in order to evaluate the size and condition of the prostate gland.


Urinalysis: Urinalysis involves laboratory testing of the urine to detect other problems that may be causing your enlarged prostate symptoms. A simple urinalysis helps to rule out bladder infection and bladder cancer, which can cause similar symptoms.

Prostate Specific Antigen Test (PSA): The PSA measures the level of prostate-specific antigen in your blood. Only prostate cells make this protein, which is important for the liquefaction of semen. Although this test is typically used to check for prostate cancer, it can also detect an enlarged prostate. A man’s PSA may actually be an indicator of whether or not he is at risk for continued prostate enlargement. This test is usually used in combination with other tests, such as the digital rectal exam, to make an accurate diagnosis.


Urodynamic Testing: Urodynamic testing involves placement of a small pressure-sensitive catheter through the urethra into the bladder; your bladder is slowly filled with water and you are then asked to urinate into a special toilet. The pressure sensitive catheter monitors pressures within the bladder and the special toilet provides information regarding your urinary stream. This test provides information about the presence and severity of interference to urine elimination.

Cystoscopy: During cystoscopy, the physician inserts a small round instrument called a cytoscope into the urethra and bladder. The cytoscope consists of a small lens and light system. This instrument allows the physician to monitor the size of the prostate gland and to determine the severity of the obstruction.


Enlarged Prostate Treatment

Men who experience minimal symptoms related to an enlarged prostate gland may choose to practice what is called watchful waiting. This means that the man will simply monitor his condition and continue to meet with his physician regularly. This is considered a reasonable option until symptoms become bothersome and interfere with quality of life. For patients suffering more severe enlarged prostate symptoms, drug therapy is usually the first option considered. Additionally, if you are diagnosed with an enlarged prostate gland, you should talk to your doctor about erectile dysfunction (ED), because an enlarged prostate gland is a major risk factor for ED.


Drug Therapy

Since enlarged prostate symptom severity is due in part to the overall size of the prostate (and the specific area of the prostate that is enlarged), and in part to increased smooth muscle tone in the urethra, there are two main classes of medications that work to alleviate those symptoms.

The first class of enlarged prostate medications is known as alpha-blockers; these medications work by relaxing the smooth muscle around the bladder neck and within the urethra. Relaxing these muscles reduces obstruction and improves urine flow. Common side effects of alpha-blockers include the following: fatigue; dizziness; drowsiness; drop in blood pressure (when going from a lying or sitting position to standing); and nasal congestion. Due to these side effects, patients taking alpha-blockers, especially the elderly, must be mindful that there is an increased risk of falls and related injuries.

The second class of enlarged prostate medications is called 5-alpha reductase inhibitors. These medicines work by blocking production of the hormone DHT. As mentioned earlier, DHT is a hormone in the body that is associated with prostate growth. These DHT blockers will stop the growth of the prostate and may actually shrink it.

The combination of these two types of medications has been shown to work more effectively in patients with enlarged prostate than either of the medications alone. However, combination therapy may increase the likelihood of experiencing side effects from the medications; therefore, it is important to analyze the benefit(s) versus the cost(s) of combination therapy. The American Urological Association (AUA) published guidelines in 2003 that recommend alpha-blockers as primary treatment for men with symptoms related to prostate enlargement, regardless of prostate size. On the other hand, 5-alpha reductase inhibitors should only be taken by men with large prostate glands.

Note: The FDA states that all drugs prescribed for erectile dysfunction (PDE-5 inhibitors) may be taken with alpha-blockers, but they should be prescribed and used with care. Talk to your provider or pharmacist about precautions and possible drug interactions.


Minimally-Invasive Therapy

Drug therapy is not effective in all patients. Therefore, some men may consider a minimally invasive procedure to reduce prostate size and urethral obstruction. These procedures are associated with some complications but are less invasive than surgery.

Transurethral Microwave Therapy: This non-surgical option can be used to treat an enlarged prostate in a single session. A special catheter encasing a tiny microwave antenna is inserted into the urethra to the level of the enlarged prostate; a controlled dose of microwave energy is then delivered to the prostate. While heat is being delivered to the enlarged prostate, cool water circulates throughout the length of the catheter in order to protect nearby tissue from excessive heat. Since the urethra is protected, the patient does not experience the serious side effects that can result from surgery. This procedure can be performed in an outpatient setting.

Transurethral Needle Ablation: Transurethral Needle Ablation is another approach to relieving obstruction without damaging the urethra. In this procedure, a small probe is inserted through the urethra; the probe delivers low level radio frequency energy to the prostate to destroy excess tissue. The procedure can be done in one session in your doctor’s office and is less invasive than surgery.



Surgery is most commonly recommended for men experiencing severe and persistent symptoms due to an enlarged prostate. There are many different types of surgeries that may be performed. The physician will choose the surgery that best fits each individual case.


Some of these surgeries include:


Transurethral Surgery: Transurethral surgery is the most common surgical procedure for treatment of an enlarged prostate, and it is currently considered the gold standard. This surgery is called Transurethral Resection of the Prostate (TURP), and is used whenever possible because it is less traumatic than procedures that require an incision. It also is better than all other procedures (except total removal of the prostate) in improving flow rates.12 In this surgery there are no external incisions. A small tool called a resectoscope is inserted through the urethra. This tool uses an electrical wire loop that cuts tissue away from the part of the enlarged prostate that is constricting the urethra. As of 1995, the rate of re-operation following the TURP procedure was very low (2.2%/year).13 Complications following TURP include erectile dysfunction (5 – 10%), incontinence (, about 3%), and infertility (need to include percentages since this info was provided for other complications).13 As is true of any surgery, there is a slim risk of death (about 1.5%). 13

A newer procedure called transurethral incision of the prostate (TUIP) is performed through the urethra, like TURP. In this procedure, a few small incisions are made to widens the urethra. This promising surgery has received good reviews but its advantages and long term side effects have not yet been clearly established. 


Open Surgery

When transurethral surgery is not a viable option, an open prostate surgery, called a prostatectomy, is performed. In open surgery an incision is made into the abdomen. This form of surgery is usually performed in the case of a significantly enlarged prostate. There are a number of different types of open procedures. The physician decides which procedure to use based on the location of the prostate and the patient’s general health.


Enlarged Prostate Conclusion

It is important for men experiencing any bothersome urinary symptoms to see their physician as soon as possible. These signs may be indicators of more serious conditions and should be diagnosed immediately. Men diagnosed with an enlarged prostate should be comforted by the wide range of treatment options available to them.