Prostate enlargement

Also known as benign prostatic hyperplasia (BPH)

Prostate enlargement is a common gradual enlargement of the prostate that occurs as men age.

The prostate is a gland found only in men. It is about the size of a walnut, lies just below the bladder and surrounds the tube (urethra) that drains urine from the bladder. Its job is to secrete a milky fluid, which becomes part of the semen and nourishes the sperm.

The prostate reaches its adult size by 20 years of age. For some men, it starts to grow again around middle age. One theory for why this occurs is that as you get older, the prostate cells become more sensitive to hormones in the bloodstream and that this makes the cells grow.

This leads to a gradual enlargement of the prostate gland and is known as benign prostatic hyperplasia (BPH). Benign means it is not cancer. Hyperplasia means enlarged. A large prostate can be the size of an apple and sometimes can grow as large as a grapefruit.

Key points

  1. Prostate enlargement usually starts in middle age.
  2. It is very common (about half of men aged over 50 and 80% of men aged 80 or more will get it).
  3. Benign means it is not cancer.
  4. While you can read about the symptoms below, do not self-diagnose, see your doctor as they may need to exclude other causes.

If you have any of the following you are at a higher risk of BPH:

  • obesity
  • lack of physical activity
  • erectile dysfunction
  • increasing age
  • family history of BPH.


As the prostate gland enlarges, it can cause narrowing of the urethra and can also lift up the base of the bladder. Further changes can happen to the bladder. Symptoms can include:

  • slow, delayed start or straining when passing urine
  • poor or variable urinary flow
  • frequency — have to go more often to pass urine
  • urinary urgency —  need to go straight away and can't hold on
  • dribbling of urine
  • nocturia — having to wake at night to pass urine multiple times
  • incomplete emptying of the bladder.

However, less than half of men with BPH have any symptoms at all.

To assess your symptoms you and your doctor could use the International Prostate Assessment Score.  It includes questions such as:

"In the last 4 weeks, how often have you noticed the following symptoms:

  • A feeling of not having emptied your bladder after you have finished urinating.
  • Needing to go again within two hours of urinating.
  • Stopping and starting while urinating.
  • Finding it difficult to wait before passing urine."

If you have urinary symptoms from the list above, it is best to see your doctor and get checked.  In addition, you should see a doctor immediately if you have any of the following:

  • blood in your urine
  • pain with urination
  • burning with urination
  • unable to urinate. 

Sometimes the narrowing of the urethra can lead to acute urinary retention - this is when you cannot pass urine at all and leads to acute pain. Immediate treatment is needed.

BPH can also cause:

  • urine to back-up in the kidneys
  • bleeding through the urethra
  • infections
  • bladder stones

All of these conditions can lead to serious health problems and must be treated.

If you have burning or pain while urinating, see your doctor right away.


Your doctor will carry out a digital rectal examination to check your prostate for any abnormality. A urine sample may be taken to test for blood, infection or other problems, such as diabetes.

If you have few symptoms, your doctor may decide simply to monitor your condition with regular check-ups. However, if your condition is complicated, medication or surgery may be suggested.

Medications can work by relaxing the muscles around the prostate or blocking the action of the hormone testosterone, shrinking the prostate.

Surgical treatment of BPH often involves removing excess prostate tissue (about 25% of men with BPH will require this).

Self care

  • Avoid or cut down on alcohol and caffeine.
  • Do not drink fluids shortly before going to bed.
  • Seek advice from your doctor.

Learn more

Enlarged-prostate-benign-prostatic-hyperplasia Southern Cross Healthcare Group (NZ), 2013
Prostate – health tips Southern Cross Healthcare Group (NZ)

Credits: Health Navigator Sept 2013. Reviewed By: Health Navigator