Enlarged Prostate (Benign Prostatic Hyperplasia)

Enlarged Prostate: Prevalence

Enlarged prostate, or benign prostatic hyperplasia (BPH), is a common occurrence among men as they age. Benign means that the enlargement is not caused by cancer or infection, or is unnatural; 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.

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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. It courses through the prostate and the penis. The prostate gland is the size and shape of a chestnut in a man's early life, enlarging later in life to variable sizes and shapes. It has an important role in sexual function producing semen, which supports sperm nourishment and transport.

In most men, the prostate gland will undergo two stages of growth. The first stage occurs in childhood and early adolescence and is usually complete by the end of puberty. The prostate remains the same size for many years but begins growing again in most men after age 40.  If the prostate becomes enlarged, it can squeeze the urethra, potentially blocking the natural flow of urine.  Blockage can also occur to the flow of semen from the attached glads that store sperm and semen, the seminal vesicles. This obstruction of urine and semen may cause a number of irritating symptoms and, if untreated, can lead to more serious problems as well.

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Enlarged Prostate: Causes

Physicians are not certain exactly why prostate enlargement occurs, but it is believed that it may be due to an excess of certain hormones in the body. One theory regarding the origin of an enlarged prostate involves the presence of a hormone called dihydrotestosterone (DHT) in the blood. DHT is a natural hormone that is responsible for the initial stages of prostate growth. As men age, DHT may cause the prostate to continue growing after it has reached full size. Studies have shown a high positive correlation between DHT levels and enlarged prostate. Physicians have noted that men who do not produce DHT do not experience an enlarged prostate. Research has also shown evidence that estrogen and genetics may play roles in BPH as well.

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 the actual size of the prostate does not necessarily denote the severity of the symptoms. Constriction of the urethra by the prostate may occur in small as well as large glands. It is important to establish the presence of obstruction by clinical testing when considering treatments for symptoms.

  • 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.

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Enlarged Prostate: Symptoms

Although men may experience varying enlarged prostate symptoms, 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
  • 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

Routine male wellness exams are recommended and should include a prostate symptom review and prostate exam. Silent obstruction of the bladder may be diagnosed when reviewing bladder function and exam findings. This is important in preventing bladder damage later in life. What matters is how significantly quality of life and freedom are impacted by the symptoms being experienced both in middle aged as well as elderly men. 

In order to determine the degree of symptoms experienced, a questionnaire such as the the International Prostate Symptom Score (IPSS) may be given to patients. It is a self-administered questionnaire used to evaluate BPH symptoms to assess their severity. Answers to each question have corresponding numerical values, known as the BPH Symptom Score Index, which are totaled to characterize the severity of symptoms.

Score       0      1      2      3      4      5

Incomplete Emptying

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?

Weak Stream

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

Along with this test your physician will most likely conduct a thorough medical history examination and a complete physical, as well as urinalysis. Depending on the individual case of each patient, additional tests may be administered. Following is a description of each of these tests:

Digital Rectal Exam: A digital rectal exam is an element of a routine physical exam. Due to the natural position of the prostate gland, an enlargement may commonly be felt through the wall of the rectum. Your physician will insert a gloved finger into the rectum in order to monitor the size and condition of the prostate gland.

Urinalysis: Urinalysis is the laboratory testing of the urine to determine if any infections or other problems are related to 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 monitors the level of prostate-specific antigen in a patient's blood. 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 Tests: Urodynamics are a group of diagnostic tests done to evaluate the performance of the lower urinary tract. These tests can reveal abnormal patterns in urination that may be a sign of an obstructing prostate, a poorly functioning bladder, or both conditions. Specifically, urodynamics investigate problems such as urine control, urinary frequency or urgency, poor bladder emptying, and intermittent urination  by measuring the bladder pressure and urinary flow. A low flow and high pressure usually indicate obstruction to the urinary outlet.

Cystoscopy: During cystoscopy, a small flexible fiberoptic camera is inserted into the urethra and bladder to evaluate the anatomy of the urethra, prostate, and bladder. 

To learn about screening for prostate cancer, check out the American Cancer Society's updated guidelines on prostate cancer screening.

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Enlarged Prostate: Treatment

Active Surveillance

Some men experiencing minimal symptoms of BPH may choose to practice what is called active surveillance. This means that the man will simply monitor his condition and continue to meet with his physician regularly until changes warrant intervention. 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. The treatments below are listed in order of the invasiveness of the therapy or procedure, from less invasive to more invasive.

Drug Therapy

There are two main classes of pharmaceuticals that work to alleviate enlarged prostate symptoms.

The first class of enlarged prostate medications includes known as alpha-blockers. These alpha-receptor blocking agents work by relaxing the smooth muscle around the bladder neck and within the urethra. Relaxing these muscles urine flow. Currently available alpha-blockers include Cardura® (doxazosin), Flomax® (tamsulosin), Uroxatral (alfuzosin hydrochloride), and RapafloTM (silodosin). 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.

Note: A 2009 study published in The Journal of the American Medical Association (JAMA) showed a significant increase in the possibility of serious complications for men after cataract surgery who have been taking Flomax. Of the 96,128 men studied, 7.5% had serious complications following surgery if they had been taking Flomax at least 14 days before surgery. Serious complications included retinal detachment, a lost lens, or inflammation. The study did not find complications with other similar medications.

The second class of enlarged prostate medications is called 5-alpha reductase inhibitors. These medications include Proscar® (finasteride) and Avodart (dutasteride) and work by inhibiting the conversion of the male hormone testosterone to DHT to reduce the gland's size and thus blockage. These DHT blockers will stop the growth of the prostate and may actually shrink it. Shrinkage of the prostate by 25% has been observed in patients treated with these medications. In addition to shrinking the prostate, research suggests that finasteride may prevent or delay the appearance of prostate cancer.13 This same research also reported that men who took the medication experienced noteworthy sexual side effects.13

The combination of these two types of medications, alpha-blockers and 5-alpha reductase inhibitors, 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. CIALIS was recently approved for daily use for those with ED who also have the signs and symptoms of BPH. CIALIS belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. PDE5 is an enzyme found in many tissues in the body; it helps prevent blood vessels from relaxing and filling up with blood. Blood flow to the penis is necessary to get and keep an erection. CIALIS blocks PDE5 and causes smooth muscle and blood vessels in the penis to relax. This relaxation leads to increased blood flow. And increased blood flow to the penis is necessary for getting and maintaining an erection. PDE5 enzymes are also found in the prostate and bladder. CIALIS inhibits PDE5 in these tissues as well, but the mechanism of how CIALIS improves BPH symptoms is not completely understood.

Minimally-Invasive Therapy

Drug therapy is not effective in all patients. Therefore, some men may consider a minimally invasive option for treating enlarged prostate symptoms. 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. In some cases, 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. This procedure delivers low-level radio frequency energy to the prostate. During the procedure,  a small probe is inserted through the urethra into the prostate tissue. The probe energy converts to heat to destroy excess tissue and cause shrinkage of the gland. If placed properly, this needle ablation treatment can significantly enlarge the prostate channel. The procedure can be done in one session in your doctor’s office and is less invasive than surgery.
  • Laser Therapy: Laser therapy is another option for men with BPH. Laser procedures perform ablation of the tissue and reduce the size of the enlarged prostate. These procedures require some type of anesthesia and sometimes an overnight hospital stay.  There are two types of laser therapy: interstitial laser coagulation (ILC) and laser vaporization. ILC is done with a laser which uses lower energy than the laser vaporization procedure. Using a lower energy laser may help reduce damage of surrounding tissue, adverse outcomes or complications, and recovery time. Targeted heating destroys tissue, and the reduction of the obstruction and the improvement of symptoms occurs gradually over time. Laser vaporization uses a higher energy laser to cause vaporization of the enlarged prostate obstruction and open the urethra. In the GreenLight™ Laser Therapy, a small fiber inserted into the urethra carries laser energy which removes tissue. This procedure provides relief more rapidly from urinary symptoms, and typically a catheter is only needed for less than 24 hours after the procedure.14 Patients undergoing the GreenLight Laser Therapy have demonstrated significant improvement in symptoms and voiding efficiency. Laser procedures are considered less invasive than TURP.

Surgery is most commonly recommended for men experiencing severe and persistent symptoms due to an obstructing 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 form of surgery for treatment of an obstructing prostate and 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 external incisions.  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 modified cystoscope called a resectoscope is inserted through the urethra and uses an electrical wire loop that cuts tissue away from the center of the enlarged prostate TURP is a preferred technique for medium to large glands. 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.13  As is true of any surgery, there is a slim risk of death (about 1.5%). 13
  • A similar procedure called transurethral incision of the prostate (TUIP) is performed through the urethra, enlarging the urethra by making an incision in the prostate and bladder neck. TUIP is most useful for small to medium glands with obstructing tissue at the bladder neck. This promising surgery has received good reviews but its advantages and long term side effects have not yet been clearly established.
  • Urethral Stent: A wire mesh stent is placed in the urethra within the prostate to gently hold the urethra open to allow the passage of urine. This is a permanent stent placed in an outpatient setting with a special delivery tool and a cystoscope, a tool that allows a lighted view of the urethra, prostate, and bladder.
  • Open Surgery: When transurethral surgery is not a viable option due to a very large gland, an open prostate surgery, called an open simple prostatectomy, is performed. This form of surgery is usually performed in the case of a significantly enlarged prostate greater than 100 cc volume. In this surgery, an incision is made in the lower abdomen just above the pubic area. The interior of the prostate is removed, leaving a shell of compressed normal prostate tissue. A significant increase in urinary flow is commonly seen after this surgery with the greatest increase in urinary flow of all treatment techniques.

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. It is also important for men without symptoms to be screened routinely. Men diagnosed with an enlarged prostate should be comforted by the fact that a wide range of treatment options available.

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Enlarged Prostate: References

  1. Berry SJ, Coffey DS, Walsh PC, et al: The Development of human benign prostatic hyperplasia with age. J Urol 1984; 132:474.
  2. Barry MJ, et al. J Urol. 1992;148:1549-1557.
  3. Dr. Siegel from NAFC's Q and A session 4.) Berry SJ, Coffey DS, Walsh PC, et al: The Development of human benign prostatic hyperplasia with age. J Urol 1984; 132:474.
  4. Shibata Y et al 2000; Gann PH et al 1995; Krieg M et al 1993
  5. Sanda MG, Doehring CB, Binkowitz B, et al: Clinical and biological characteristics of familial benign prostatic hyperplasia. J Urol 1997; 157:876.
  6. Dr. Siegel from NAFC's Q and A session
  7. Dr. Siegel from NAFC's Q and A session
  8. Kasraeian A. Recent Update in benign prostatic hyperplasia. Jacksonville Medicine. 1998;6-9.
  9. AUA Guideline on Management and Benign Prostatic Hyperplasia. Chapter 1: Diagnosis and Treatment Recommendations. J Urol 2003; 170:N2.
  10. Medina JJ, Parra RO, Moore RG. Benign Prostatic Hyperplasia (The aging prostate). Med Clin North Am. 1999.;83(5): 1213-1229.
  11. Payne R. Evaluation and Medical Treatment of Benign Prostatic Hyperplasia presentation.
  12. JE Oesterling. Benign prostatic hyperplasia. Medical and minimally invasive treatment options. New England Journal of Medicine 1995 332: 99-109.
  13. Thompson, Ian et al. The Influence of Finasteride on the Development of Prostate Cancer. The New England Journal of Medicine 2003 349:215-224.
  14. Sarica K, Alkan E, Luleci H, Tasci AI. Photoselective vaporization of the enlarged prostate with KTP laser: long-term results in 240 patients. J Endourol. 2005 Dec;19(10):1199-202.

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