Enlarged Prostate (BPH): Symptoms, Causes, Diagnosis and Treatment Options

What BPH is

The prostate surrounds the urethra just below the bladder. From the mid-thirties onward it slowly enlarges, driven mainly by dihydrotestosterone (DHT), a potent form of testosterone produced within the gland. Benign prostatic hyperplasia (BPH) is the medical name for this enlargement when it is large enough to cause symptoms or be detected on examination.

It is extremely common. Microscopic enlargement is present in about half of men in their fifties and 80–90% of men in their eighties; roughly half of those with enlargement have bothersome symptoms. BPH is benign: it does not become cancer and does not spread. Its consequences are mechanical.

What happens inside the body

Two things produce the symptoms.

Obstruction. The enlarging gland squeezes the urethra where it passes through the prostate, and the smooth muscle within the gland and at the bladder neck tightens. Urine has to pass through a narrower channel, so the stream weakens, takes longer to start, and the bladder may not empty completely.

Bladder irritation. The bladder muscle works harder against the obstruction, thickens, and becomes overactive — contracting at low volumes and producing urgency, frequency and night-time waking. Over years, a chronically overworked bladder can lose its ability to contract effectively, which is one reason treatment is not delayed indefinitely.

Symptoms correlate poorly with gland size. A moderately enlarged prostate can cause severe symptoms if the growth is in the part that surrounds the urethra; a very large one can cause few.

Symptoms

Doctors group these as lower urinary tract symptoms (LUTS):

Obstructive (voiding) symptoms - weak or slow stream - hesitancy — waiting for flow to start - straining - intermittent stream that stops and starts - dribbling at the end - a feeling of incomplete emptying

Irritative (storage) symptoms - urgency — a sudden strong need to go - frequency — going more than about eight times a day - nocturia — waking at night to urinate, often the most bothersome symptom - urge incontinence in some cases

Symptoms typically develop over years. See weak urine stream and frequent urination at night for what each can mean.

Causes and risk factors

Age and functioning testes are the two requirements; men castrated before puberty do not develop BPH. Beyond that, risk is higher with a family history of BPH, obesity, metabolic syndrome, diabetes, physical inactivity and, in some studies, high blood pressure. There is no evidence that sexual activity, vasectomy or diet cause it.

Possible complications

Most men with BPH never develop complications. When they occur, they include:

• Acute urinary retention — sudden inability to pass urine, painful, requiring a catheter. Can be triggered by cold medicines, alcohol, anaesthesia or constipation.
• Chronic retention — a bladder that never fully empties, often painless, sometimes discovered only through overflow leakage or kidney effects.
• Recurrent urinary tract infections from stagnant urine.
• Bladder stones.
• Blood in the urine, from enlarged surface vessels on the gland.
• Kidney damage from long-standing high-pressure retention — uncommon but serious.

How doctors diagnose it

• Symptom questionnaire — the International Prostate Symptom Score (IPSS) rates seven symptoms from 0 to 5; scores of 8–19 are moderate, 20+ severe. It is used both for diagnosis and to track treatment.
• Digital rectal examination — estimates gland size and feels for irregularity that would suggest cancer.
• Urine test to exclude infection and blood.
• PSA blood test — raised in BPH as well as cancer, so interpreted with size and age in mind. It also predicts which glands will keep growing.
• Post-void residual — an ultrasound measurement of urine left in the bladder after voiding.
• Uroflowmetry — measures the speed of the stream.
• Bladder diary for men with frequency and nocturia.

Cystoscopy, imaging and pressure-flow studies are reserved for unusual cases or before surgery.

Treatment

Treatment is matched to how bothersome symptoms are, not to gland size.

Watchful waiting and lifestyle measures

For mild symptoms (IPSS under 8) or symptoms that do not bother the man, no treatment is needed beyond annual review. Simple measures help at any stage:

• reduce fluids in the two hours before bed, and limit caffeine and alcohol, which irritate the bladder and increase urine production
• empty the bladder before leaving the house, and try "double voiding" — waiting a moment and going again
• review medications: decongestants and antihistamines can worsen obstruction; diuretics timed in the evening worsen nocturia
• treat constipation, which presses on the bladder neck
• bladder training to lengthen the interval between voids

Medication

Alpha-blockers (tamsulosin, alfuzosin, silodosin, doxazosin) relax the smooth muscle of the prostate and bladder neck. They improve symptoms within days, do not shrink the gland, and are the usual first choice. Side effects include dizziness on standing, tiredness and reduced ejaculation; they can complicate cataract surgery, so tell your eye surgeon.

5-alpha reductase inhibitors (finasteride, dutasteride) block the conversion of testosterone to DHT and shrink the prostate by about 20–25% over six to twelve months. They are most useful for larger glands and reduce the risk of retention and surgery. Side effects in a minority include reduced libido, erectile difficulty and breast tenderness. They halve PSA, which must be accounted for in cancer screening.

Combination of the two is common for men with larger glands and moderate to severe symptoms.

Tadalafil (5 mg daily), a PDE5 inhibitor, improves urinary symptoms as well as erectile function and is an option for men with both.

Antimuscarinics or beta-3 agonists (for example mirabegron) are added when storage symptoms — urgency, frequency — persist despite an alpha-blocker.

Minimally invasive procedures

For men whose symptoms do not respond to medication, who do not want long-term medication, or who develop complications, several office- or day-case procedures are available, each with a different balance of effectiveness, durability and side effects: prostatic urethral lift (UroLift), water vapour thermal therapy (Rezūm), prostate artery embolization, and others. They generally preserve ejaculation better than surgery, with somewhat less durable benefit.

Surgery

Transurethral resection of the prostate (TURP) remains the standard operation, removing the obstructing inner tissue through the urethra. Laser techniques (HoLEP, GreenLight) achieve similar results with less bleeding. Very large glands may need a different approach. Surgery gives the largest and most durable improvement; retrograde ejaculation is common afterwards and a small proportion of men have persistent incontinence or erectile problems.

When to contact a doctor

Arrange an appointment if urinary symptoms are bothering you, if you have to get up more than once or twice a night, if you see blood in your urine, or if you have a fever with urinary symptoms. Seek same-day care if you cannot pass urine at all, or can pass only small amounts with a painful, swollen lower abdomen — acute retention needs a catheter.

Can supplements play a supportive role?

Some men also explore dietary supplements as part of a broader wellness routine. Supplements do not shrink the prostate, do not prevent retention, and should not replace assessment or prescribed treatment.

Saw palmetto is the most used and most studied; the largest and best-designed trials, including the NIH-funded CAMUS trial, found it no better than placebo. Beta-sitosterol has modest evidence in older trials. Does saw palmetto work for an enlarged prostate? sets out the evidence; the saw palmetto and beta-sitosterol pages cover doses and safety. Tell your doctor about any supplement you take, particularly before a PSA test.

Frequently asked questions

References