My Procedure

Water vapor thermal therapy (Rezum)

Rezum treats an enlarged prostate with small, measured puffs of steam injected through a scope in the urethra. The heat kills the extra prostate cells, and over the next few months the body clears them away and the prostate shrinks.

Also called Rezum, Rezūm, water vapor therapy, water vapor thermal therapy, WVTT, steam treatment for prostate, steam prostate procedure, convective radiofrequency water vapor therapy

Where
Clinic procedure room or outpatient surgery center
Anesthesia
Local numbing (often a nerve block next to the prostate) with an oral sedative, or IV sedation
Time in the room
About 1 hour in the room; the steam treatments themselves take only a few minutes
Hospital stay
Same day
Going home with
Catheter for about 3 to 7 days
Back to normal
A few days for daily life; urinary symptoms improve over 2 weeks to 3 months
Back to work
Often within 2 to 3 days, with the catheter in place if needed
See the steps
BladderProstateUrethraBladder neck
Where it happens. The highlighted part is what this procedure treats.

Overview

In BPH (benign prostatic hyperplasia), the inner prostate grows and squeezes the urethra, the tube that carries urine out. Rezum uses the heat stored in water vapor (steam) to treat that extra tissue. A small needle is passed through a scope into the prostate, and a 9-second puff of steam is released. As the steam turns back into water, it gives off its heat to the cells around it, and those cells die.

Nothing is removed during the procedure. Over the next several weeks, the body absorbs the treated tissue and the prostate shrinks, opening the channel. That is why improvement is gradual, starting around 2 weeks and reaching its full effect around 3 months.

The AUA guideline lists Rezum as an option for prostates about 30 to 80 grams. Unlike UroLift, it can treat a middle lobe. In the Rezum II trial, men did not have new lasting erection problems, and most kept normal ejaculation. About 4 in 100 men needed another procedure within 5 years.

The main downsides are that the prostate swells before it shrinks, so almost every man needs a catheter for several days, and the first few weeks can bring burning, urgency, and some blood.

The parts of your body involved

The prostate sits below the bladder and wraps around the urethra. In BPH, the side lobes grow inward and sometimes a middle lobe grows up into the bladder outlet. The steam is placed inside these lobes, in the inner (transition) zone, where BPH grows.

  • Side lobes

    The main overgrown tissue. Several steam treatments are placed along each one.

  • Middle lobe

    If present, it can be treated with its own steam injections.

  • Urethra

    The channel the scope passes through. It opens as the prostate shrinks.

  • Bladder neck

    The outlet of the bladder, just above the prostate.

Why it’s done

Rezum is for men with bothersome BPH symptoms who want a short procedure without general anesthesia, want to protect sexual function, and are willing to wait a few months for the full effect.

  • Symptoms despite medicines

    Pills are not working well enough or cause side effects.

  • Protecting ejaculation

    Most men keep normal ejaculation after Rezum.

  • Middle lobe

    Rezum can treat a middle lobe, which some other office options cannot.

  • Avoiding general anesthesia

    It is usually done with local numbing and a calming medicine.

Other options

  • Watching and waiting or medicines

    Lifestyle changes, alpha blockers, 5-alpha reductase inhibitors, or tadalafil.

  • UroLift

    Implants hold the lobes apart. Often no catheter, faster relief, but not for a blocking middle lobe and a higher retreatment rate.

  • iTind

    A temporary device reshapes the channel over about a week.

  • TURP or HoLEP

    Removing tissue gives larger improvement and lower retreatment, but usually dry orgasms.

  • Prostate artery embolization

    Shrinks the prostate by blocking its blood supply through an artery.

Getting ready

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Weeks before

The week before

The day of

The procedure, step by step

Press play or pick a step. Each drawing shows what your surgeon is doing at that moment. Your team may do some steps differently.

Leg supportsSurgeonVideo screen
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1. Getting comfortable

You lie back with your legs in supports. A calming medicine, by mouth or through an IV, helps you relax. Monitors check your heart rate and oxygen.

  1. You lie back with your legs in supports. A calming medicine, by mouth or through an IV, helps you relax. Monitors check your heart rate and oxygen.

  2. Numbing gel goes into the urethra. Many urologists also numb the nerves beside the prostate with a thin needle, guided by an ultrasound probe in the rectum or a finger. This feels like pressure and a short sting.

  3. The Rezum handpiece, a slim scope with a hidden needle, is passed through the urethra to the prostate.

  4. On the screen, the urologist sees the lobes pressing together and plans where to place each puff of steam, starting about 1 cm below the bladder neck.

  5. A thin needle slides out of the scope into the side lobe. You may feel a quick pinch or pressure.

  6. Steam is released into the lobe for about 9 seconds. It spreads between cells and gives off its heat, treating a zone of tissue about 1.5 cm across. You may feel warmth, a cramp, or a strong urge to urinate.

    More detail

    The steam is held inside the boundaries of the prostate's inner zone, so the heat stays where it is aimed. Cool rinse fluid protects the lining of the urethra.

  7. The needle is pulled back, the scope moves about 1 cm further down, and the next treatment is given. This repeats along both side lobes. Bigger prostates need more treatments.

  8. If you have a middle lobe, it gets its own steam treatments.

  9. The treated tissue swells for several days, so a catheter is placed to drain urine while the swelling settles.

After the procedure

Right afterward

  • Short rest

    You rest until the sedative wears off, usually 30 to 60 minutes.

  • Catheter teaching

    A nurse shows you how to use the leg bag and night bag.

  • Medicines

    You usually go home with an antibiotic, an anti-inflammatory, and sometimes medicine for bladder spasms.

  • Going home

    Someone drives you home the same day.

At home

  • Catheter

    The catheter usually stays about 3 to 7 days. Keep the bag below your bladder and wash where the tube enters the penis daily.

  • Discomfort

    Pelvic aching and bladder spasms are common in the first days. Anti-inflammatory medicine helps if your team approves it.

  • After the catheter

    Burning, frequency, urgency, and small amounts of blood are common for 2 to 4 weeks, sometimes longer. Your stream may be weaker before it gets better.

  • Bits in the urine

    Small pieces of treated tissue may pass for several weeks.

  • Drinking

    Drink plenty of water. Limit caffeine and alcohol.

  • Activity

    Light activity right away. Avoid heavy lifting and strenuous exercise for about a week or as advised.

  • Sex

    Usually after about 2 weeks or when comfortable. Some blood in the semen for a few weeks is common and harmless.

Recovery timeline

  1. Day 0
    Procedure

    Home the same day with a catheter.

  2. Days 3 to 7
    Catheter out

    Removed at a clinic visit, or at home if you were taught how.

  3. Weeks 1 to 2
    The irritable phase

    Burning, urgency, and a stream that may not yet be better.

  4. About 2 weeks
    First improvement

    Many men start to notice easier urination.

  5. 1 to 3 months
    Steady gains

    The prostate keeps shrinking and symptoms keep improving.

  6. 3 months
    Full effect and follow-up

    Symptoms, flow, and emptying are checked.

  7. Long term
    Durability

    In the Rezum II trial, improvement lasted through 5 years for most men.

What it feels like

The procedure itself is short. What men remember is the warmth and urge with each puff of steam, a week with a catheter, and a few weeks of feeling worse before they feel better.

  1. During the steam

    A brief warm, cramping sensation and a strong urge to urinate, lasting about 9 seconds each time.

    What helpsThe team counts down each treatment. Slow breathing helps.

  2. The catheter week

    Awareness of the tube, bladder spasms, and some embarrassment going out.

    What helpsA leg bag under loose pants is hard to see. Spasm medicine helps.

  3. After the catheter comes out

    Frustration that the stream may still be weak, with burning and urgency.

    What helpsThis is expected while tissue swells and clears. Improvement usually starts around 2 weeks.

  4. Seeing debris

    Bits of tissue or a little blood in the urine.

    What helpsNormal for several weeks. Call if clots block your stream.

  5. Three months on

    Easier urination and fewer night trips, with sex life unchanged for most men.

    What helpsKeep your follow-up visit.

How well it works

Most men notice clear improvement by 3 months. The benefit is generally less than TURP or HoLEP but comes with a better chance of protecting ejaculation.

  • Symptoms

    In the Rezum II trial, symptom scores improved by about half and stayed improved through 5 years.

  • Sexual function

    No new lasting erection problems were seen. A few men notice less semen.

  • Retreatment

    About 4 in 100 men in the Rezum II trial needed another procedure within 5 years.

  • Later options

    If needed, TURP, HoLEP, or another treatment can still be done later.

Risks

Every operation has risks. These are the ones people ask about most, with honest odds where good numbers exist. Your surgeon’s own results matter more than averages.

Common

Burning, frequency, and urgency

For several weeks, especially after the catheter comes out.

Blood in urine or semen

Usually mild and short-lived.

Catheter for several days

Needed in almost all men because of swelling.

Less common

Not able to urinate after the catheter comes out

The catheter may be put back for a few more days.

Urine infection

Treated with antibiotics.

Less semen at orgasmAbout 3 in 100 men

A few men notice less fluid.

Need for another procedureAbout 4 in 100 men within 5 years

Symptoms may come back or not improve enough.

Rare

New lasting erection problems

Not seen in the main trial, but any prostate procedure carries a small risk.

Scar narrowing

Rarely, scar tissue forms in the urethra.

Heat injury beyond the prostate

Very rare because the steam stays inside the prostate's inner zone.

Call your care team or go to the emergency room if

  • Fever of 101°F (38.3°C) or higher, or shaking chills
  • No urine draining from your catheter for 1 hour, especially with belly pain
  • Not able to urinate for 6 hours after the catheter comes out
  • Thick red urine or clots that block the flow
  • Severe pain that does not improve with your medicines

Questions to ask your surgeon

  1. Is my prostate a good size and shape for Rezum?
  2. How many steam treatments do you expect I will need?
  3. Will I be awake? What numbing do you use?
  4. How long will I have the catheter?
  5. When should I expect to feel better?
  6. What are the chances of changes in ejaculation?
  7. How likely is it that I will need another procedure later?
  8. How many Rezum procedures have you done?

Words you may hear

Water vapor thermal therapy
Using the heat in steam to treat prostate tissue.
Transition zone
The inner part of the prostate where BPH grows.
Middle lobe
Prostate growth that pushes up into the bladder outlet.
Catheter
A soft tube that drains urine from the bladder.
Prostate block
Numbing medicine injected next to the prostate to reduce pain.
BPH
Benign prostatic hyperplasia: non-cancer growth of the prostate.
Retreatment
Needing another procedure for the same problem later.
IPSS
A symptom questionnaire scored from 0 to 35.

Common questions

Why do I need a catheter if Rezum is so small?

The treated tissue swells for several days before it shrinks. The catheter keeps urine flowing while that happens.

When will I feel better?

Many men notice a change around 2 weeks, with full benefit around 3 months.

Will it affect my sex life?

In the main trial, men did not have new lasting erection problems, and most kept normal ejaculation. A few notice less semen.

Does it hurt?

Most men feel warmth, cramping, and urgency during each 9-second treatment. Numbing and a sedative make it manageable for most.

Can Rezum be repeated?

Yes. It can be repeated, or another treatment can be used if needed.

Sources this page draws on

  • American Urological Association, Management of Lower Urinary Tract Symptoms Attributed to Benign Prostatic Hyperplasia (BPH): AUA Guideline
  • European Association of Urology, EAU Guidelines on the Management of Non-neurogenic Male Lower Urinary Tract Symptoms
  • Rezum II study investigators (McVary and colleagues), Rezum II randomized controlled trial and its 5-year results
  • Urology Care Foundation, Benign Prostatic Hyperplasia (BPH)

Written November 2026. This page explains what usually happens. It is not medical advice and does not replace a conversation with your own surgeon, whose plan for you comes first.

Related procedures

UroLiftEnlarged prostate
iTindEnlarged prostate
Optilume BPHEnlarged prostate
TURPEnlarged prostate
HoLEPEnlarged prostate