What is the prostate and what function does it have in the body?

The prostate gland is a small organ.  It forms part of the male sexual or reproductive anatomy.  Other parts include the penis, scrotum, and testes.

The prostate sits deep in the pelvis, between the penis and the bladder.  On average, it is roughly the size of a walnut or a ping-pong ball.  It weighs around 30 grams.  It is usually soft and smooth to the touch.  It is possible to feel the prostate gland by placing a finger into the rectum and pressing toward the front of the body.

The prostate has various functions.  The most important is the production of seminal fluid, a component of semen.  The muscles of the prostate ensure that the semen is forcefully pressed into the urethra and then expelled outwards during ejaculation.  It also plays a role in hormone production and helps to regulate urine flow.

The urethra, a tube that carries urine and semen out of the body, passes through the prostate.  Because the prostate surrounds this tube, prostate problems can affect urine flow.

Prostate specific antigen (PSA)

Prostate-specific antigen, or PSA, is a protein produced by normal, as well as cancerous, cells of the prostate gland.

PSA is mostly found in semen, but small amounts of PSA can also be found in the blood.  A PSA test measures the level of PSA in the blood.  A PSA test is a blood test to help check for prostate problems.  Prostate problems are common, especially in older men.  The most common include an inflamed prostate, an enlarged prostate and prostate cancer.

What does the results of a PSA test mean?

PSA levels depend on age.  PSA levels naturally go up with age.  But PSA can go up and down for many reasons.  Most labs consider a normal PSA level to be around 4 ng/mL.

A higher-than-normal PSA level doesn't mean that you have prostate cancer.  High PSA levels can also be caused by:

• An enlarged prostate due to benign prostatic hyperplasia (BPH).
• An inflamed or infected prostate (prostatitis).
• A urinary tract infection.
• A recent medical test or procedure on the prostate, such as a biopsy.
• A urinary catheter or bladder exam.
• Bike riding often or a recent long bike ride.

When is a PSA test requested?

Prostate conditions often cause problems with urination or bladder control.  Testing may be recommended if you have symptoms that could indicate prostate cancer or problems, such as:

• Urinating more than usual.
• Having a sudden urge to urinate, sometimes with only a small amount of urine.
• Getting up often in the night to urinate.
• Difficulty starting the urine stream, or stopping and starting the stream while urinating.
• Blood in the urine.
• A weak or thin urine stream.
• Problems getting or keeping an erection.

Prostate problems can also cause problems with sexual function, urinary tract infections, bladder stones, or in extreme cases, kidney failure.  If the symptoms are caused by cancer, finding it early may mean it's easier to treat.

For more information on prostate cancer, please click here.