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• Highlights
• Introduction
• Symptoms
• Causes of Benign Prostatic Hyperplasia
• Causes of Lower Urinary Tract Symptoms
• Risk Factors
• Complications
• Diagnostic Tests
• Treatment
• Lifestyle Changes
• Medications
• Other Treatments
• Resources
• References

Benign prostatic hyperplasia

Description

An in-depth report on the causes, diagnosis, treatment, and prevention of BPH.

Alternative Names

Enlarged prostate

Introduction

Hyperplasia is a general medical term referring to excess cell replication. Benign prostatic hyperplasia (BPH), also called benign prostate hyperplasia, is a noncancerous growth of the prostate gland. It is the most common noncancerous form of cell growth in men and usually begins with microscopic nodules in younger men. BPH, however, is not a precancerous condition. Prostate cancer usually occurs in the outer area of the prostate, called the peripheral zone.

As BPH progresses, overgrowth occurs in the central area of the prostate, called the transition zone, which wraps around the urethra (the tube that carries urine through the penis). This pressure on the urethra can cause lower urinary symptoms that have been the basis for diagnosing BPH. In 2000, an expert committee suggested that the impact of such symptoms on quality of life, including sexual activity, is also important in assessment of the disease.

The Prostate Gland

Description of the Prostate Gland. The prostate gland is located between the bladder and the rectum and wraps around the urethra (the tube that carries urine through the penis) . It is basically composed of three different cell types:

• Glandular cells, which produce a milky fluid that liquefies semen.
• Smooth muscle cells, which contract during sex and squeeze the fluid from the glandular cells into the urethra, where it mixes with sperm and other fluids to make semen. The muscle cells are stimulated by molecules called alpha adrenergic receptors.
• Stromal cells (which form the structure of the prostate).

The central area of the prostate that wraps around the urethra is called the transition zone. The entire prostate gland is surrounded by a dense, fibrous capsule.

Functions of the Prostate Gland. The prostate gland provides the following functions:

• The glandular cells produce a milky fluid, and during sex the smooth muscles contract and squeeze this fluid into the urethra. Here, it mixes with sperm and other fluids to make semen.
• The prostate also secretes another substance that may have antibacterial properties.
• The prostate gland also contains an enzyme called 5 alpha-reductase that converts testosterone to dihydrotestosterone, another male hormone with as a major impact on the prostate.

Changes During the Lifespan. The prostate gland undergoes many changes during the course of a man's life. At birth, the prostate is about the size of a pea. It grows only slightly until puberty, when it begins to enlarge rapidly. It reaches normal adult size and shape, about that of a walnut, when a man is in his early 20s. The gland generally remains stable until about the mid-40s, when, in most men, the prostate begins to grow again through a process of cell multiplication.

Hormonal changes also occur in the prostate gland. Testosterone levels fall while dihydrotestosterone remain at normal levels.

• Review Date: 6/26/2006
• Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital

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