What Is The Main Cause Of Prostate Enlargement?

Prostate enlargement is one of the most common conditions affecting men in the UK. By the age of 60, more than half of men will have some degree of it, and by their seventies and eighties, that figure rises to around 90%.

Yet despite its widespread prevalence, many men are unsure what actually causes it – or whether it can be prevented.

What is prostate enlargement?

The prostate is a small, walnut-sized gland that sits just below the bladder and surrounds the urethra (the tube through which urine passes). Its primary role is to produce fluid that nourishes and transports sperm.

When the prostate grows larger than normal, it can squeeze the urethra, making it harder for urine to flow freely. This condition is medically known as benign prostatic hyperplasia (BPH) – “benign” because, unlike prostate cancer, it is not malignant and does not spread to other parts of the body.

The main cause? Hormonal changes with age

The primary cause of prostate enlargement is the hormonal shift that naturally occurs as men get older.

Throughout a man’s life, the prostate goes through two main phases of growth – once during puberty, and again from around the age of 25 onwards. This second phase is gradual and largely driven by changes in the balance of sex hormones, particularly the rise in dihydrotestosterone (DHT).

DHT is a potent derivative of testosterone that plays a key role in prostate cell growth. As testosterone levels decline with age, the ratio of oestrogen to testosterone in the body shifts. Higher relative oestrogen levels appear to sensitise prostate tissue to DHT, which in turn stimulates the overproduction of prostate cells – leading to the glandular enlargement associated with BPH.

This hormonal process is the reason why BPH is so closely tied to age. It rarely causes symptoms before 40, but becomes increasingly common with each passing decade.

Other factors that can contribute

While hormonal ageing is the root cause, several other factors can influence the likelihood and severity of prostate enlargement:

Family history: Men with a first-degree relative who has had BPH are at greater risk of developing it themselves, suggesting a genetic component.
Obesity and metabolic syndrome: Excess body fat – particularly around the abdomen – is associated with higher oestrogen levels and increased inflammation, both of which can accelerate prostate growth. Maintaining a healthy weight is one of the most effective modifiable risk factors.
Type 2 diabetes: Insulin resistance and elevated insulin levels have been linked to increased prostate cell proliferation.
Cardiovascular disease: Research suggests a relationship between heart disease, high blood pressure, and BPH, likely due to shared risk factors such as sedentary lifestyle and poor diet.
Diet: Diets high in red meat, saturated fat, and refined carbohydrates may promote prostate growth, while diets rich in vegetables, healthy fats, and plant-based proteins appear to be protective.

How does prostate enlargement affect the body?

As the prostate enlarges, it presses inward against the urethra. The bladder, forced to work harder to push urine through the narrowed channel, gradually becomes thickened and overactive. Over time, it may lose the ability to empty fully, leaving residual urine behind.

This is why the most recognisable symptoms of BPH are urinary in nature. If you are experiencing any of the following, it is worth speaking to a specialist:

Difficulty passing urine or a noticeably weak flow
Needing to urinate more frequently, particularly at night
A sudden, urgent need to urinate that is hard to control
A feeling that the bladder has not fully emptied
Dribbling at the end of urination

Left unmanaged, BPH can lead to more serious complications, including urinary tract infections, bladder stones, and in severe cases, damage to the bladder or kidneys. Our blog on things to avoid with prostate enlargement outlines some useful practical guidance for managing the condition day to day.

Is it BPH or something else?

It is important to note that not all urinary symptoms are caused by BPH. Prostatitis – inflammation of the prostate – can produce similar complaints and affects men of all ages. Prostate cancer can also be present alongside BPH without causing additional symptoms in its early stages, which is why a thorough assessment is essential rather than assuming any urinary change is simply down to age.

An elevated PSA (prostate-specific antigen) level can be a sign of both BPH and prostate cancer, so understanding your PSA reading in the right clinical context matters.

Our guide on what is a dangerous PSA level explains more about how these results are interpreted.

What are the treatment options for BPH?

The good news is that prostate enlargement is very treatable, and there are options to suit men at all stages of the condition.

For mild to moderate symptoms, lifestyle changes and medication – including alpha-blockers to relax the muscles around the urethra, and 5-alpha reductase inhibitors to reduce DHT levels and shrink the prostate – can provide significant relief.

Where medication is insufficient, a range of minimally invasive and surgical procedures are available:

UroLift: Small implants that hold the enlarged prostate tissue away from the urethra, with no cutting or removal of tissue required
TURP (transurethral resection of the prostate): The established surgical standard, removing the inner portion of the prostate to widen the urinary channel
GreenLight laser vaporisation and holmium laser enucleation (HoLEP) – laser-based procedures offering effective results with reduced bleeding and faster recovery

The right treatment will depend on the size of the prostate, the severity of symptoms, and individual patient factors – all of which can be assessed during a specialist consultation.

When should you seek advice?

Urinary symptoms can feel embarrassing to raise, but prostate enlargement is as common a part of ageing as any other age-related change. Seeking advice early – before symptoms significantly affect quality of life or complications develop – leads to better outcomes and a wider range of treatment choices.

At Urocare London, Consultant Urologist Mr Maneesh Ghei provides expert diagnosis and tailored treatment for BPH and all other prostate conditions. If you have concerns about your urinary health, do not put off getting the answers you need.

Maneesh Ghei

Mr Maneesh Ghei MS MRCSEd MD (UCL) FRCS (Urol) is a highly experienced Consultant Urological Surgeon and founder of Urocare London, with over three decades of practice in both NHS and private settings across the capital. As Lead Cancer Clinician at Whittington Hospital, Archway, he chairs the multidisciplinary urology cancer meeting, overseeing patient care from diagnosis through to the latest minimally invasive treatments. A pioneer in complex endourology and stone disease management, Mr Ghei led the UK’s first randomised, double-blind trial of intradetrusor botulinum toxin for refractory overactive bladder. He holds an MBBS and MS in General Surgery from India, an MD from University College London, and undertook advanced fellowships in stone disease and laparoscopic surgery, culminating in his Fellowship of the Royal College of Surgeons (Urology). Committed to education and research, he supervises doctoral work in focal therapies and cryotherapy for prostate cancer and champions public awareness through annual Movember fundraising.