The prostate is a gland the size of a chestnut. It is only present in men, and it is situated under the bladder surrounding the urethra, the passageway that takes the urine to the outside. The gland produces seminal fluid, which is mixed with sperm to make semen.

With age, the gland may begin to grow - this happens to most men. The growth may eventually cause problems with urination, because the gland pinches off the urethra as it increases its size.

The growth in itself is harmless and so the condition is called benign prostate hyperplasia (BPH). It occurs most often in men over the age of 60. Up to 30 per cent of men in their 70s have BPH that causes them symptoms.

Prostate enlargement varies in severity from man to man, and doesn't always pose a problem. Only about half the men with prostate enlargement experience signs and symptoms that become noticeable or bothersome enough for them to seek medical treatment. These signs and symptoms may include:

• Weak urine stream
• Difficulty starting urination
• Stopping and starting again while urinating
• Dribbling at the end of urination
• Frequent need to urinate
• Increased frequency of urination at night (nocturia)
• Urgent need to urinate
• Not being able to completely empty the bladder
• Blood in the urine (hematuria)
• Urinary tract infection