Prostatomegaly is the medical term for an enlarged prostate gland. It describes a prostate that has grown beyond its normal size of roughly 25 milliliters (about the size of a walnut), and it’s most commonly caused by a noncancerous condition called benign prostatic hyperplasia, or BPH. Nearly all men experience some degree of prostate enlargement as they age, and while it isn’t dangerous on its own, it can compress the urinary tract and cause symptoms that range from mildly annoying to seriously disruptive.
How the Prostate Grows and Why
The prostate sits just below the bladder and wraps around the urethra, the tube that carries urine out of the body. During puberty, testosterone is converted into a more potent hormone called dihydrotestosterone (DHT) inside the prostate, which drives the gland to its adult size. This conversion process never fully stops. As men age, DHT continues to signal prostate cells to multiply, and the gland gradually enlarges over decades.
Researchers don’t fully understand why some men develop significant enlargement while others don’t, but androgen signaling through DHT is the central driver. This is so well established that one of the main drug treatments works by blocking the enzyme responsible for that testosterone-to-DHT conversion, effectively shrinking the gland over time.
Common Symptoms
Because the prostate surrounds the urethra, even modest enlargement can squeeze the urinary channel and interfere with normal bladder function. The cluster of problems this creates is often called lower urinary tract symptoms, and it includes:
- Frequent or urgent need to urinate, including waking multiple times at night
- Difficulty starting urination or a weak, stop-and-start stream
- Dribbling at the end of urination
- Feeling like your bladder hasn’t fully emptied
These symptoms tend to develop gradually. Many men adapt to them without realizing how much their quality of life has changed until the symptoms become severe. The degree of bother doesn’t always match the size of the prostate. Some men with moderately enlarged glands have significant symptoms, while others with very large prostates have relatively few complaints.
Grades of Enlargement
A normal adult prostate measures about 25 milliliters and weighs between 15 and 25 grams. Doctors generally consider a prostate enlarged once it reaches 30 milliliters or more. From there, severity is sometimes graded by volume:
- Grade 1: 25 to 30 mL
- Grade 2: 31 to 50 mL
- Grade 3: 51 mL and above
These volume measurements are typically obtained through ultrasound imaging. The most common method uses a rectal ultrasound probe to measure the prostate’s width, height, and length, then plugs those three numbers into a formula that estimates the total volume. The procedure is quick and gives doctors a reliable baseline to track growth over time.
PSA and Ruling Out Cancer
If you’re told your prostate is enlarged, your doctor will likely check your PSA level with a blood test. PSA is a protein produced by the prostate, and its levels naturally rise as the gland gets bigger. Men with prostate volumes over 30 mL typically have PSA levels above 1.5 ng/mL, simply because there’s more prostate tissue producing the protein.
The challenge is that prostate cancer also raises PSA. The test cannot reliably tell the difference between benign enlargement and cancer on its own. Prostate cancer has been found at every PSA level, including very low ones. A PSA between 0 and 4 ng/mL, long considered the “normal” range, still carries roughly a 15 to 25 percent chance of cancer depending on the specific level. When PSA is elevated or rising, doctors typically recommend a biopsy to get a definitive answer. An enlarged prostate does not mean cancer, but it does mean the PSA test needs careful interpretation rather than a simple pass/fail reading.
What Happens Without Treatment
Left unmanaged, a progressively enlarging prostate can lead to complications beyond everyday urinary bother. Chronic incomplete bladder emptying creates a pool of stagnant urine that raises the risk of urinary tract infections and bladder stones. Over time, the bladder muscle itself can weaken from constantly straining against the obstruction, eventually losing its ability to contract effectively. In severe cases, urine can back up into the kidneys, a condition called hydronephrosis, which can cause kidney damage. Acute urinary retention, a sudden complete inability to urinate, is a medical emergency that requires a catheter to drain the bladder.
Medication Options
Two main classes of drugs are used to treat prostatomegaly, and they work in very different ways. Alpha blockers relax the smooth muscle around the prostate and bladder neck, making it physically easier for urine to flow. They don’t shrink the prostate, but they can improve symptoms within days to weeks.
The second class, 5-alpha reductase inhibitors, targets the root cause by blocking the enzyme that converts testosterone to DHT. With less DHT stimulating growth, the prostate actually shrinks. In longer-term studies, these drugs reduced prostate volume by about 18 to 27 percent over three to four years. The tradeoff is patience: noticeable improvement typically takes several months. Many men end up taking both drug types together, one for quick symptom relief and the other for long-term volume reduction.
Procedural Treatments
When medications aren’t enough, or when a man prefers a more definitive fix, several procedures can physically reduce the amount of prostate tissue blocking the urethra. The traditional approach, called transurethral resection, involves removing excess prostate tissue through a scope inserted via the urethra. It’s highly effective but carries risks of urinary incontinence, retrograde ejaculation (where semen flows backward into the bladder during orgasm), and sexual dysfunction.
Newer, less invasive options have expanded the choices considerably. Two of the most common are water vapor therapy (Rezūm) and a mechanical lift system (UroLift). Both are recommended for prostates between 30 and 80 grams and are specifically designed to preserve erectile and ejaculatory function, which makes them appealing for sexually active men. Water vapor therapy has shown strong durability even in larger prostates over 80 mL, with a surgical retreatment rate of only about 1.2 percent in long-term follow-up studies. These procedures are typically done as outpatient visits, and recovery is significantly shorter than with traditional surgery.
The right treatment depends on prostate size, symptom severity, whether complications like retention or stones have developed, and personal priorities around sexual function and recovery time. Most men start with medication and move to procedures only if symptoms persist or worsen.