English: Anatomy of Urinary bladder

English: Anatomy of Urinary bladder (Photo credit: Wikipedia)

The prostate is a male gland that is important in the production of semen, the fluid that contains sperm.  The prostate gland is around the urine tube from the bladder.  While the size of a walnut in younger men, it grows larger as men age and can become so large that it creates real problems.  Generally, these problems become more prevalent after age 50.  
Prostate-specific antigen (PSA) is a protein produced by prostate cells.  Higher than normal levels of PSA are associated with prostate cancer.  The PSA levels in blood will vary depending on age.  However, it will require a biopsy to determine if cancer is present.

NORMAL RESULTS

Normal PSA blood levels are:
Less than 2.5 for men under 50
Less than 3.5 for men aged between 50 to 59
Less than 4.5 for men aged between 60 to 69
Less than 6.5 for men aged 70 and above

HIGHER THAN NORMAL RESULTS

Higher than normal PSA levels can be caused by:
Prostate cancer
Enlarged prostateProstate infection
Urinary tract infection