Rezum Water Vapour Therapy for an Enlarged Prostate: What It Does, and What to Expect Afterwards

最終更新日： 8月 25, 2026

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Rezum treats an enlarged prostate with water vapour instead of cutting. It was approved by the US FDA in 2015, it takes minutes rather than an operating list, and — the reason most men are interested — it protects sexual function in a way that conventional prostate surgery does not.

It is a genuinely useful option. This article also sets out the parts men are least often told beforehand, because those are what determine whether someone is satisfied with the result.

Related reading: what benign prostatic enlargement actually is · how water vapour shrinks the prostate · patient instructions after the procedure

• 泌尿器センター バンコク病院 タイ オンライン予約 02-310-3009 bhquro@bdms.co.th
• サミティジ・シラチャ病院 チョンブリ 088-022-1445

How it works

A telescope is passed along the urethra and a fine needle injects a burst of sterile water vapour into the bulky part of the prostate. The vapour spreads through the tissue and releases its stored heat, killing the cells it reaches. Nothing is scooped out or cut away. Over the following weeks the body reabsorbs the treated tissue, the gland shrinks from within, and the channel opens.

That mechanism explains both its main advantage and its main limitation. Because it is targeted and shallow, the nerves and structures responsible for erection and ejaculation are largely left alone. Because it relies on the body clearing dead tissue gradually, nothing happens quickly.

What to expect in the first weeks — the part usually left out

An earlier version of this article said men notice significant improvement within a month, and stopped there. That is roughly true of the endpoint and quite misleading about the journey.

• A catheter is needed afterwards, usually for a few days, because the treated prostate swells before it shrinks. This is expected, not a complication.
• The first two to three weeks are often worse than before treatment. Burning, urgency, going more frequently, and blood or debris in the urine are all normal in this window. Men who are not warned about this reasonably conclude the procedure has failed.
• Improvement builds over months rather than days. Most men are clearly better by around three months, and the result continues to settle after that.

If you cannot tolerate a few uncomfortable weeks — because of work, travel, or simply preference — that is a legitimate reason to choose a different treatment, and it is better discussed before than discovered after.

Advantages and limitations

What it offers	What it does not
Sedation rather than a general anaesthetic in most cases	Fast relief — the benefit builds over weeks to months
Day case, no overnight stay	An avoidance of catheters — one is needed for several days afterwards
Ejaculation preserved in the great majority, unlike prostate resection where loss of ejaculate is the norm	A guarantee against sexual side effects — uncommon is not the same as never
Short procedure, quick return to normal activity	Permanence in every case — a proportion of men need a further procedure years later
Reasonable option for men on blood-thinning medication, after discussion	Help for symptoms coming from the bladder rather than the prostate

Corrections to the earlier version of this table

Three entries have been changed, and it is worth saying why.

• It listed no erectile dysfunction complication as an absolute. Preservation of sexual function is the genuine strength of this procedure and the main reason to choose it over resection — but it is stated here as very likely rather than certain, because no procedure carries a zero rate.
• It listed a history of urinary retention as making a man unsuitable. Men in retention were excluded from the original trials, but later series have reported treating catheter-dependent men successfully. It is a matter for individual assessment rather than an automatic exclusion.
• It gave 120 mL as a flat upper limit without saying where the number came from. The distinction now made is between two different things: the trials that established this treatment enrolled prostates of roughly 30 to 80 mL, which is where the evidence is strongest, while treating up to around 120 mL is reasonable in practice on weaker evidence and by individual judgement. Above that, resection or enucleation is generally the better operation. A man of 100 mL is not excluded — he is simply being treated in the territory where the published data thins out, and he is entitled to know that.

Previous prostate radiotherapy and recurrent urinary infection remain genuine reasons for caution.

The honest comparison with prostate resection

Transurethral resection removes obstructing tissue directly. It produces a bigger improvement in flow, it works immediately, and it has decades of long-term data behind it. Its price is a general or spinal anaesthetic, a hospital stay, and loss of ejaculation for most men.

Rezum asks less of the body and protects ejaculation, and accepts in exchange a slower and somewhat smaller improvement, with a meaningful minority of men needing something further within five years. Neither is better in the abstract. A man in his fifties for whom ejaculation matters and a man of eighty in retention are answering different questions.

Symptoms that need attention rather than a routine appointment

Whether you are considering the procedure or recovering from it, get medical attention the same day for any of the following. In an emergency in Thailand, call 1669.

• Complete inability to pass urine with a painful full bladder.
• Fever or shaking chills after the procedure.
• Heavy bleeding, or clots that block the flow. Lightly blood-stained urine in the early weeks is expected; clots that stop you passing urine are not.
• A catheter that stops draining, or falls out before the planned removal date.

お客様からよくいただくご質問

Q1: What is Rezum and how does it treat an enlarged prostate?

A needle passed down a telescope injects sterile water vapour into the bulky part of the prostate. The heat carried by the vapour kills the cells it reaches, and over the following weeks the body reabsorbs that tissue so the gland shrinks and the channel opens. No tissue is cut or removed.

Q2: Will it affect my sex life?

This is its main advantage. Ejaculation is preserved in the great majority of men, whereas after prostate resection most men no longer ejaculate externally. Erectile function is generally unaffected. That said, uncommon is not the same as never, and an earlier version of this article claimed no sexual complication at all, which overstated it.

Q3: How soon will I feel better?

Expect the first two to three weeks to be worse rather than better — burning, urgency, frequency and blood in the urine are normal in that window, and a catheter is needed for a few days at the start. Clear improvement usually appears by around three months and continues to settle after that.

Q4: Is it permanent, or will I need it again?

Most men treated do not need anything further, but a minority require a second procedure or an operation within five years. This is a real difference from resection and belongs in the decision. Anyone quoting Rezum as a permanent cure is overselling it.

Q5: Who is not suitable?

Previous prostate radiotherapy and recurrent urinary infection are genuine reasons for caution. On size: the trials enrolled prostates of roughly 30 to 80 mL, and treating up to around 120 mL is reasonable in practice on weaker evidence; above that, resection or enucleation is usually the better operation. A history of retention is no longer an automatic exclusion, though it does change the discussion. Assessment includes measuring the prostate and testing the flow — and, importantly, confirming that the prostate is the cause of the symptoms at all, since an underactive or overactive bladder produces similar complaints and is not improved by treating the prostate.

Q6: Is Rezum available in Bangkok?

Yes, at Bangkok Hospital Headquarters, where Dr. Soarawee performs it. He introduced water vapour prostate therapy during his years leading the urology department in Phnom Penh.

相談の手続きをする

Dr. Soarawee Weerasopone sees patients at バンコク病院本部 そしてチョンブリー県のサミティベート・シーラチャ病院にて 088-022-1445. Bring any previous prostate measurements, flow tests and PSA results.

バンコク病院の遠隔医療は、来院が困難な患者様（海外からの患者様を含みます）を対象にご利用いただけます。泌尿器科宛てに事前にメールでご手配ください。 bhquro@bdms.co.th. サミティベート・シラチャは対面診療のみです。料金に関するお問い合わせは当ウェブサイトではなく、病院にお問い合わせください。.

免責事項 この記事の内容は、バンコク病院本社（Bangkok Hospital Headquarters）の認定泌尿器科医であるソラウィー・ウィーラソポン医師（Dr. Soarawee Weerasopone）が執筆および監修したものであり、教育目的のみを意図しています。これは医学的なアドバイス、診断、または個別の処方ではなく、個人的なメッセージングチャンネルやソーシャルメディアを通じてアドバイス、診断、処方が行われることはありません。ソラウィー医師は公開のソーシャルメディアアカウントを運営していません。彼の名前で個人的な相談を提供しているアカウントはすべて詐欺です。タイで緊急事態が発生した場合は、以下にお電話ください。 1669.