The prostate is a male reproductive gland tasked with producing the fluid that carries sperm out of the body during ejaculation. The prostate surrounds the urethra, the tube through which urine passes during urination. As men age, the prostate gland grows bigger. It is originally about the size of a walnut, often increasing in size by the age of 40 to the size of an apricot. By the time a man is 60 years old, his prostate gland may have enlarged to the size of a lemon. The enlarged prostate ends up squeezing the urethra like a clamp on a garden hose, causing the flow of urine to become weak and slow. The condition is also known as benign prostatic hyperplasia, or BPH. It’s not cancerous, and it doesn’t increase a man's risk of contracting prostate cancer.
More than 50 % of men in their sixties have symptoms of enlarged prostates due to BPH, and that number rises to many as 90 % when men reach their seventies and eighties.
The causes of enlarged prostate are not well understood. The only two risk factors doctors have been able to associate with enlarged prostate are growing old and having a functioning set of testicles. Men who have had their testicles removed when they were young do not develop BPH.
Other explanations for an enlarged prostate include:
* Decreased testosterone level. The amount of testosterone in the blood decreases as a man ages. When that occurs, the proportion of naturally occurring estrogen in a man's body increases, and may promote growth of the prostate.
* Increased DHT level. The prostate derives a substance called dihydrotestosterone, or DHT, from testosterone. Even though blood testosterone levels drop in older men, DHT production doesn’t slow down, so high levels of DHT continue to build up in the prostate. This could lead to the growth of prostate cells.
* Genetics. It has also been suggested that genetic instructions inside some prostate cells may order them to activate later in life and begin to grow.
An enlarged prostate also can result from a prostate infection or from prostate cancer, although those occur less frequently and are not as inevitable as BPH.
The symptoms of enlarged prostate always revolve around a problem with the ability to urinate. Men might find that they can only maintain a hesitant, weak stream that frequently stops. They also may need to urinate more frequently, because the bladder is not completely emptied with each episode of urination, particularly at night. There is usually no pain involved in BPH; if there is pain, it could mean an infection has occurred.
There's no way to prevent BPH. It occurs as a function of aging.
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