The prostate is a walnut-size gland in a man's reproductive system that makes and stores seminal fluid. It is below the bladder and in front of the rectum, and it surrounds the upper part of the urethra, the tube that empties urine from the bladder.

As men age, the prostate enlarges through a process of cell multiplication called benign prostatic hyperplasia (BPH).

Urinary problems, but not necessarily cancer, often result as the prostate presses against the urethra and bladder, interfering with the normal urine flow. By the time men make it to their 70s, four out of five will have developed enlarged prostates.

Along the way, some men also are troubled by an inflammation of the prostate -- a condition called prostatitis.

But the most feared male health problem is prostate cancer. All men are at risk for developing prostate cancer, and a man has about a one in ten chance of developing prostate cancer in his lifetime.

Prostate cancer begins in the prostate gland's cells. If cell division is abnormal, a mass of tissue called a tumor forms. If not caught and treated in time, the cancerous cells can spread through the blood and lymph fluid to other organs, tissues and bones.

The American Cancer Society estimates that 189,000 men in the United States will be diagnosed with prostate cancer this year, and about 30,200 men will die.

By age 50, up to one man in four is believed to have cancerous cells in his prostate gland. By age 80, prostate cancer cells will be present in one man in two.

Many of these men will die of prostate cancer. But most will not. Because prostate tumors are low-grade and often slow growing, survival rates are excellent when prostate cancer is detected early.

In this section, you will find more information about the different diseases of the prostate, and particularly prostate cancer. You will learn about the risk factors, and the tests designed to help men detect prostate cancer at an early stage when it is highly curable.