Practice EssentialsBenign prostatic hyperplasia (BPH), also known as benign prostatic hypertrophy, is a histologic diagnosis characterized by proliferation of the cellular elements of the prostate, leading to an enlarged prostate gland. Chronic bladder outlet obstruction (BOO) secondary to BPH may lead to urinary retention, impaired kidney function, recurrent urinary tract infections, gross hematuria, and bladder calculi. The image below illustrates normal prostate anatomy. Show Signs and symptomsWhen the prostate enlarges, it may constrict the flow of urine. Nerves within the prostate and bladder may also play a role in causing the following common symptoms:
See Presentation for more detail. DiagnosisDigital rectal examination The digital rectal examination (DRE) is an integral part of the evaluation in men with presumed BPH. With the DRE, the examiner can assess prostate size and contour, evaluate for nodules, and detect areas suggestive of malignancy. Laboratory studies
Ultrasonography Ultrasonography (abdominal, renal, transrectal) is useful for helping to determine bladder and prostate size and the degree of hydronephrosis (if any) in patients with urinary retention or signs of renal insufficiency. Generally, it is not indicated for the initial evaluation of uncomplicated LUTS. Endoscopy of the lower urinary tract Cystoscopy may be indicated in patients scheduled for invasive treatment or in whom a foreign body or malignancy is suspected. In addition, endoscopy may be indicated in patients with a history of sexually transmitted disease (eg, gonococcal urethritis), prolonged catheterization, or trauma. IPSS/AUA-SI The severity of BPH can be determined with the International Prostate Symptom Score (IPSS)/American Urological Association Symptom Index (AUA-SI) plus a disease-specific quality of life (QOL) question. Questions on the AUA-SI for BPH concern the following:
Other tests
See Workup for more detail. ManagementPharmacologic treatment Agents used in the treatment of BPH include the following:
Surgery
Minimally invasive treatment
See Treatment and Medication for more detail. For patient education information, see Enlarged Prostate (BPH) Symptoms, Diagnosis, Treatment. BackgroundBenign prostatic hyperplasia (BPH), also known as benign prostatic hypertrophy, is a histologic diagnosis characterized by proliferation of the cellular elements of the prostate. Cellular accumulation and gland enlargement may result from epithelial and stromal proliferation, impaired preprogrammed cell death (apoptosis), or both. BPH involves the stromal and epithelial elements of the prostate arising in the periurethral and transition zones of the gland (see Pathophysiology). The hyperplasia presumably results in enlargement of the prostate that may restrict the flow of urine from the bladder. BPH is considered a normal part of the aging process in men and is hormonally dependent on testosterone and dihydrotestosterone (DHT) production. An estimated 50% of men demonstrate histopathologic BPH by age 60 years. This number increases to 90% by age 85 years. The voiding dysfunction that results from prostate gland enlargement and bladder outlet obstruction (BOO) is termed lower urinary tract symptoms (LUTS). It has also been commonly referred to as prostatism, although this term has decreased in popularity. These entities overlap; not all men with BPH have LUTS, and likewise, not all men with LUTS have BPH. Approximately half of men diagnosed with histopathologic BPH report moderate-to-severe LUTS. Clinical manifestations of LUTS include urinary frequency, urgency, nocturia (awakening at night to urinate), decreased or intermittent force of stream, or a sensation of incomplete emptying. Complications occur less commonly but may include acute urinary retention (AUR), impaired bladder emptying, the need for corrective surgery, renal failure, recurrent urinary tract infections, bladder stones, or gross hematuria. (See Presentation.) Prostate volume may increase over time in men with BPH. In addition, peak urinary flow, voided volume, and symptoms may worsen over time in men with untreated BPH (see Workup). The risk of AUR and the need for corrective surgery increases with age. Patients who are not bothered by their symptoms and are not experiencing complications of BPH should be managed with a strategy of watchful waiting. Patients with mild LUTS can be treated initially with medical therapy. Transurethral resection of the prostate (TURP) is considered the criterion standard for relieving bladder outlet obstruction (BOO) secondary to BPH. However, there is considerable interest in the development of minimally invasive therapies to accomplish the goal of TURP while avoiding its adverse effects [2] (see Treatment). AnatomyThe prostate is a walnut-sized gland that forms part of the male reproductive system. It is located anterior to the rectum and just distal to the urinary bladder. It is in continuum with the urinary tract and connects directly with the penile urethra. It is therefore a conduit between the bladder and the urethra. (See the image below.) Benign prostatic hyperplasia. Normal prostate anatomy is shown. The prostate is located at the apex of the bladder and surrounds the proximal urethra.The gland is composed of several zones or lobes that are enclosed by an outer layer of tissue (capsule). These include the peripheral, central, anterior fibromuscular stroma, and transition zones. BPH originates in the transition zone, which surrounds the urethra. PathophysiologyProstatic enlargement depends on the potent androgen dihydrotestosterone (DHT). In the prostate gland, type II 5-alpha-reductase metabolizes circulating testosterone into DHT, which works locally, not systemically. DHT binds to androgen receptors in the cell nuclei, potentially resulting in BPH. However, the fact that serum testosterone levels decrease with age, yet the development of BPH increases, suggests that other agents play an etiologic role. Possible factors include the metabolic syndrome, hyperinsulinemia, norepinephrine, angiotensin II, and insulin-like growth factors. [3] In vitro studies have shown that large numbers of alpha-1-adrenergic receptors are located in the smooth muscle of the stroma and capsule of the prostate, as well as in the bladder neck. Stimulation of these receptors causes an increase in smooth-muscle tone, which can worsen LUTS. Conversely, blockade of these receptors (see Treatment) can reversibly relax these muscles, with subsequent relief of LUTS. Microscopically, BPH is characterized as a hyperplastic process. The hyperplasia results in enlargement of the prostate that may restrict the flow of urine from the bladder, resulting in clinical manifestations of BPH. The prostate enlarges with age in a hormonally dependent manner. Notably, castrated males (ie, who are unable to make testosterone) do not develop BPH. The traditional theory behind BPH is that, as the prostate enlarges, the surrounding capsule prevents it from radially expanding, potentially resulting in urethral compression. However, obstruction-induced bladder dysfunction contributes significantly to LUTS. The bladder wall becomes thickened, trabeculated, and irritable when it is forced to hypertrophy and increase its own contractile force. This increased sensitivity (detrusor overactivity), even with small volumes of urine in the bladder, is believed to contribute to urinary frequency and LUTS. The bladder may gradually weaken and lose the ability to empty completely, leading to increased residual urine volume and, possibly, acute or chronic urinary retention. In the bladder, obstruction leads to smooth-muscle-cell hypertrophy. Biopsy specimens of trabeculated bladders demonstrate evidence of scarce smooth-muscle fibers with an increase in collagen. The collagen fibers limit compliance, leading to higher bladder pressures upon filling. In addition, their presence limits shortening of adjacent smooth muscle cells, leading to impaired emptying and the development of residual urine. The main function of the prostate gland is to secrete an alkaline fluid that comprises approximately 70% of the seminal volume. The secretions produce lubrication and nutrition for the sperm. The alkaline fluid in the ejaculate results in liquefaction of the seminal plug and helps to neutralize the acidic vaginal environment. The prostatic urethra is a conduit for semen and prevents retrograde ejaculation (ie, ejaculation resulting in semen being forced backwards into the bladder) by closing off the bladder neck during sexual climax. Ejaculation involves a coordinated contraction of many different components, including the smooth muscles of the seminal vesicles, vasa deferentia, ejaculatory ducts, and the ischiocavernosus and bulbocavernosus muscles. EpidemiologyBPH is a common problem that affects the quality of life in approximately one third of men older than 50 years. BPH is histologically evident in up to 90% of men by age 85 years. As many as 14 million men in the United States have symptoms of BPH. [4] Worldwide, approximately 30 million men have symptoms related to BPH. The prevalence of BPH in white and African-American men is similar. However, BPH tends to be more severe and progressive in African-American men, possibly because of the higher testosterone levels, 5-alpha-reductase activity, androgen receptor expression, and growth factor activity in this population. The increased activity leads to an increased rate of prostatic hyperplasia and subsequent enlargement and its sequelae. PrognosisIn the past, chronic end-stage BOO often led to renal failure and uremia. Although this complication has become much less common, chronic BOO secondary to BPH may lead to urinary retention, chronic kidney disease, recurrent urinary tract infections, gross hematuria, and bladder calculi. Patient EducationPatients should be informed that the following lifestyle changes may help relieve symptoms of BPH:
Patients should be warned that if they become unable to urinate, they are at risk for permanent kidney or bladder injury and need to go to a hospital emergency department. For patient education information, see Enlarged Prostate (BPH) Symptoms, Diagnosis, Treatment.
Author Levi A Deters, MD Attending Physician, Spokane Urology Disclosure: Nothing to disclose. Coauthor(s) Raymond J Leveillee, MD, FRCS(Glasg) Professor of Clinical Urology, Radiology and Biomedical Engineering, Department of Urology, University of Miami Miller School of Medicine; Chief, Division of Endourology/Laparoscopy and Minimally Invasive Surgery, Department of Urology, Jackson Memorial Hospital Raymond J Leveillee, MD, FRCS(Glasg) is a member of the following medical societies: American Urological Association, Endourological Society, Sigma Xi, The Scientific Research Honor Society, Society of Laparoendoscopic Surgeons Disclosure: Received honoraria from ACMI/Gyrus for speaking and teaching; Received honoraria from Boston Scientific for speaking and teaching; Received honoraria from Applied Medical for speaking and teaching; Received honoraria from Intuitive Surgical for speaking and teaching; Received grant/research funds from Intio for other. Charles R Moore, MD Endourology Fellow, Department of Urology, University of Miami School of Medicine Charles R Moore, MD is a member of the following medical societies: Alpha Omega Alpha, American Urological Association Disclosure: Nothing to disclose. Specialty Editor Board Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference Disclosure: Received salary from Medscape for employment. for: Medscape. Chief Editor
Edward David Kim, MD, FACS Professor of Urology, Department of Urology, University of Tennessee Graduate School of Medicine; Consulting Staff, University of Tennessee Medical Center Edward David Kim, MD, FACS is a member of the following medical societies: American Society for Reproductive Medicine, American Urological Association, Sexual Medicine Society of North America, Society for Male Reproduction and Urology, Society for the Study of Male Reproduction, Tennessee Medical Association Disclosure: Serve(d) as a speaker or a member of a speakers bureau for: Endo, Antares. Acknowledgements The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous author Vincent G Bird, MD, to the development and writing of the source article. What are 3 functions of the prostate gland?The prostate has various functions. The most important is producing seminal fluid, which is a component of semen. It also plays a role in hormone production and helps regulate urine flow. Prostate problems are common, especially in older men.
What does the prostate actually do?The prostate's most important function is the production of a fluid that, together with sperm cells from the testicles and fluids from other glands, makes up semen. The muscles of the prostate also ensure that the semen is forcefully pressed into the urethra and then expelled outwards during ejaculation.
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