Important information about the prostate: a normal prostate is the size of a chestnut and is located under the bladder, where the urethra decends.

It produces fluids to transport sperm. At around 45 years of age, it often begins to grow, and can block the flow of urine. Changes in prostatic size can also be malignant. 

Typical signs of prostate-related illness:
Frequent urination during the day and night
Delayed begin or dripping at the end of urination
Persistent and intense desire to urinate
Pain during urination

How is this tested?
Ultrasound from abdomen or anus
Palpation of the prostate
Markers in blood and urine
Radiological procedures and techniques

Checkups help discover prostatic illness at a curable stage. After reaching 40 years of age, every man should have a yearly checkup.