Enlarged Prostate Facts

July 1, 2024

This page was reviewed under our medical and editorial policy by Wesley Yip, M.D., assistant professor, Division of Urology and Urologic Oncology, Department of Surgery, City of Hope^® Cancer Center Duarte

The prostate is a small gland located just below the bladder in men. It surrounds part of the urethra, the tube that drains urine from the bladder. The prostate provides the fluid that helps make up semen.

Benign prostatic hyperplasia (BPH) is a medical condition in which the prostate grows larger than normal. Health care providers may also call it benign prostatic hypertrophy, benign prostatic obstruction, enlarged prostate or simply BPH.

An enlarged prostate is a very common condition for men, especially as they age. In fact, it is the most common prostate problem for men over the age of 50 and may affect up to 90% of men over age 80.

What Is BPH?

BPH is the overgrowth of tissue in the prostate gland. Although an enlarged prostate may increase prostate-specific antigen (PSA) levels in the blood, it is important to note that benign prostatic hyperplasia is not associated with prostate cancer. BPH may affect the urinary tract, but it is a treatable condition.

As men age, the prostate grows. In some men, the prostate may get bigger without squeezing the urethra closed. In other men, the prostate may grow into the urethra, making the opening narrower. When this happens, the bladder has to work harder to get urine out.

Unfortunately, the bladder becomes more irritable when it works harder — meaning it does not tolerate holding urine well. In extreme cases, the prostate may grow into the bladder, creating a ball valve that closes off and completely stops the stream of urine trying to leave the bladder.

What Causes an Enlarged Prostate?

As men age, they experience two separate periods of growth in the prostate. The first occurs during early puberty, while the second begins around 25 years of age. This second period of growth continues for the rest of the man’s life and may lead to an enlarged prostate.

As an example, a man in his 20s typically has a prostate the size of a walnut. By age 40, it may have grown to the size of an apricot. Then, by the time he is 60, the prostate may be the size of a lemon.

Medical researchers are not sure what causes some men to have BPH while others do not. Some theories as to the causes of benign prostatic hyperplasia include:

• Changes in the testicles that come with age
• An imbalance in blood levels of testosterone and estrogen
• Higher-than-average levels of dihydrotestosterone (DHT), another type of male hormone

BPH Risk Factors

The following risk factors may be associated with an enlarged prostate:

• Age 40 years and older
• Health conditions such as type 2 diabetes, heart and circulatory disease as well as obesity
• Lack of physical exercise
• Family history of benign prostatic hyperplasia
• Erectile dysfunction