What do you mean by an enlarged prostate?

An enlarged prostate means that the prostate gland size has grown bigger. It is referred to as benign prostate hypertrophy or benign prostate hyperplasia (BPH, in short), or prostate adenoma. BPH is typically nonmalignant and hence the name.

It is essentially age-related and very common among older males. It is accompanied by bothersome lower urinary tract symptoms and is the most common cause of lower urinary tract symptoms in men.

The normal size of the prostate

Urologists use the volume parameter rather than weight to characterize the prostate size

  • A small prostate has a volume of 30 ml to 40 ml and a weight of 20 g to 70 g.
  • A medium-sized prostate has a volume of 40 ml to 80 ml and a weight of 20 g to 125g.
  • A large prostate has a volume of 40ml to 100 ml and a weight of 40 g to 125 g.

The prostate in man begins to grow around the age of 40 years. With BPH, the man’s prostate can increase by 4 to 5 times its normal size.

BPH often comes to light when the patient first presents with lower urinary tract symptoms such as frequent urination, urinary leakage, or even sexual dysfunction.

The diagnostic criteria and treatment guidelines are laid down. The digital rectal examination, PSA levels, and ultrasound give you a confirmed diagnosis. Treatment for BPH depends on the severity of the symptoms and can vary from no treatment to medication, to surgery.

Causes of benign prostate hyperplasia

The exact reason why the prostate gland enlarges is not yet known. However, changes in the male sex hormones that happen with aging may be responsible.

With advanced aging, there are changes in the testicular cells as well as in the testosterone hormone levels.

Men whose testicles have been removed at a young age (for example, due to testicular cancer) do not develop BPH.

Again, if the testicles are removed after a man develops BPH, the prostate begins to shrink in size. However, this is not to be considered the normal practice to treat an enlarged prostate.


Let’s understand the physiological process behind the development of the enlargement. BPH is clinically a histological diagnosis characterized by abnormal proliferation of the smooth muscle and epithelial cells of the prostate tissue within the transitional zone of the prostate.

There is an increase in the number of stromal and epithelial cells in the periurethral area of the prostate and hence it is referred to as hyperplasia.

The etiology of this hyperplasia is still uncertain. It may be due to uncontrolled proliferation or impaired program of the cell death leading to cellular accumulation. Microscopically, the cells appear normal but their numbers are vastly increased.

Prostate enlargement depends on the strong hormone androgen dihydrotestosterone (DHT). In the prostate gland, the enzyme type II 5-alpha-reductase converts testosterone into DHT. DHT binds to androgen receptors in the cell nuclei, potentially and in a benign manner increasing the size of the prostate.

BPH is a hyperplastic process. The resulting enlargement causes urethral compression because the surrounding capsule of the prostate prevents the gland from growing outward. This gives rise to lower urinary tract symptoms.

Risk factors

Many risk factors make you prone to develop BPH. Among them, aging is the strongest factor followed by chronic progressive disease, obesity, and metabolic syndrome.

Age and BPH

You will hardly ever see BPH in men younger than 30 years. In men above 50 years, 50% to 75% of the men experience enlargement of the prostate. Among men over the age of 70 years, 80% are impacted and by the age of 85 years, the number climbs to 90%.


Evidence strongly suggests a strong genetic link in men with BPH. An immediate relative such as a father or brother with prostate enlargement strongly predisposes you to this condition. A male parent increases your risk fourfold and a brother with BPH increases your risk sixfold.

Sex hormones

As explained above, the prostate gland is typically androgen-dependent and is highly reactive to sex hormone levels. The risk of BPH increases in people with higher levels of DTH.

Metabolic syndrome (MS) is a high-risk factor for BPH

Several studies have shown a link between metabolic syndrome and BPH. MS is characterized by a pro-inflammatory state in the blood. Studies have shown that high C-reactive proteins caused by increased inflammation may be associated with intraprostatic inflammation of BPH.


Abdominal obesity and increased levels of leptin (a hormone that sends a signal when the stomach is full after eating) are associated with an increased risk of developing BPH.

Researchers also found that high levels of leptin were significantly correlated with high-volume BPH,

Abdominal obesity, measured by body mass index, waist circumference, body fat, and visceral fat composition, was significantly associated with the development of BPH


Increasing epidemiologic evidence suggests that diabetes significantly increases the risks of BPH and lower urinary tract symptoms (LUTS).

There are several mechanisms by which diabetes may influence BPH, the first being changes in insulin concentrations that may, in turn, influence sex hormone concentrations, sympathetic nerve activity, and/or the insulin-like growth factor axis. All can affect the growth of the prostate

Physical activity

Increased physical exercise has been consistently linked to decreased risk of developing BPH. An analysis of 11 studies shows that regular moderate to vigorous exercise reduced the risk of BPH by as much as 25% in comparison to a sedentary lifestyle.


Moderate intake of alcohol protects you from developing BPH. Studies conducted show a 35% decreased likelihood of developing BPH in men who drank daily.


Oxidative stress, inflammatory mediators, and insulin growth pathway promote prostate growth. Also STDs like gonorrhea, Chlamydia, and trichomonas increase PSA levels and prostate size.

Symptoms of BPH

When the prostate is enlarged, it can irritate the bladder neck or even block the bladder. The need to urinate often is a common symptom of BPH. This might be every one to two hours, mainly at night.

LUTS (lower urinary tract symptoms) include a cluster of symptoms related to problems with the lower urinary tract, which include the bladder, prostate, and urethra.

These include

A. Voiding or obstructive symptoms such as 

  • hesitancy
  • poor and/or intermittent stream
  • straining
  • prolonged urination
  • a feeling of incomplete emptying of the bladder
  • dribbling

B. Storage or irritative symptoms such as

  • increased frequency
  • the urgency to pass urine
  • urge incontinence
  • nocturia

Less common signs and symptoms include:

  • Urinary tract infection
  • Inability to urinate
  • Hematuria (blood in the urine)

The severity of the symptoms does not necessarily tell you the size of the prostate. Men with slightly enlarged prostates can have severe symptoms, while other men with much enlarged prostates can present with minor symptoms. In some men, symptoms eventually become stable and might even improve over time.

If BPH becomes severe, it might completely block your urethra and you might not be able to urinate at all. This is called retention of urine must be treated on an emergency basis.

If you have any of these symptoms, you must see your doctor immediately:

  • Pain in the pelvic area (the lower abdomen) or genitals while urinating
  • Cannot urinate at all
  • Pain and fever while urinating.
  • Blood in the urine

Complications of untreated BPH

  • Urinary retention. Acute urinary retention (AUR) is the inability to urinate even when your bladder is full. This is a medical emergency and is treated as such. A catheter is inserted into your bladder through the urethra to drain the urine. Some men may need surgery to relieve urinary retention.
  • Urinary tract infection (UTI). UTI is a fallout of the inability of men with BPH to completely empty the bladder. It can also be caused by long-term inflammation or infection in the prostate (chronic prostatitis). Men with BPH who experience frequent, recurrent and symptomatic UTI should be considered for long-term suppressive antimicrobial treatment. Frequent episodes of UTI may require surgery.
  • Bladder stones. Bladder stones form because of the inability in men with BPH to empty the bladder completely. Due to chronic urinary retention, there is enough time for crystals and stones to form in the bladder.
  • Bladder damage. Due to chronic residual urine in the bladder, the muscles of the bladder are constantly stretched. They weaken over time and the bladder is unable to contract properly making it more difficult to empty the bladder.
  • Kidney damage. Chronic residual urine in the bladder causes bladder infection, which can travel upwards to the kidneys. This can become chronic, ultimately damage the kidneys, and even cause renal failure.