Nephrostomy tube
A nephrostomy tube is a thin, flexible tube placed through the skin of your back directly into the kidney, so urine can drain into a bag outside your body. It is usually placed by an interventional radiologist using ultrasound and X-ray, with numbing medicine and sedation.
Also called nephrostomy, percutaneous nephrostomy, PCN, PCN tube, PNT, nephrostomy drain, kidney drain, kidney tube
- Where
- Interventional radiology procedure room
- Anesthesia
- Numbing medicine with IV sedation; general anesthesia in some cases
- Time in the room
- 30 to 60 minutes
- Hospital stay
- Depends on the illness behind it: often 1 or more nights with infection, same day when planned
- Going home with
- Nephrostomy tube and drainage bag, changed about every 2 to 3 months while needed
- Back to normal
- Site soreness settles in a few days; daily life continues with the bag
- Back to work
- Depends on the reason for the tube; many people return within 1 to 2 weeks
Overview
A nephrostomy tube drains urine straight from the kidney, out through a small opening in your back, into a bag. It bypasses everything below the kidney, including the ureter (the tube that normally carries urine down to the bladder). The tube is about 3 to 4 millimeters wide. Inside the kidney it forms a small locking loop, called a pigtail, that keeps it from slipping out.
Most nephrostomy tubes are placed by an interventional radiologist, a doctor who does procedures guided by ultrasound, X-ray and CT. You usually lie face down, awake but sedated, with numbing medicine in the skin. Urologists also place nephrostomy tubes at the end of PCNL stone surgery.
The most urgent reason for a nephrostomy is a kidney that is both blocked and infected. Urine trapped behind a stone can turn to pus, and the infection can spread to the blood. Draining the kidney, along with antibiotics, can be lifesaving. For this emergency, a nephrostomy tube and a ureteral stent work about equally well, and the choice depends on how sick you are, the blockage, and what can be done fastest and most safely.
Some people need a tube for only a few days. Others, such as people whose ureters are pressed by cancer, may live with one for months. Learning to care for the tube and bag is a big part of this page.
The parts of your body involved
Your kidneys sit in the back of your belly, just under the lowest ribs, on either side of the spine. Urine collects in cup-shaped chambers called calyces and drains into a central funnel, the renal pelvis, before entering the ureter. When the ureter is blocked, urine backs up and the drainage system swells (hydronephrosis). The tube enters through the muscles of the back and the outer layer of the kidney into a calyx on the back side, then curls in the renal pelvis. Above the kidney sits the lining of the lung, and beside it the colon, so the radiologist uses imaging to choose a safe path.
- Kidney
Makes urine. The tube passes through its outer layer, which has a rich blood supply.
- Calyces and renal pelvis
The drainage chambers inside the kidney. They swell when blocked, which makes them easier to target on ultrasound.
- Ureter
The tube to the bladder. The blockage is usually here, below the kidney.
- Back muscles and skin
The tube passes through them. The skin opening is where you will do dressing care.
- Neighbors
Lung lining above, colon beside, and the spleen or liver above. Imaging keeps the path clear of them.
Why it’s done
A nephrostomy tube is placed when urine cannot drain from the kidney and needs a way out now, or when the kidney needs to be reached from the back.
- A blocked, infected kidney
Fever or sepsis with a blocked kidney is an emergency. Draining it with a nephrostomy or a stent, plus antibiotics, comes first. The stone is treated later.
- A stent cannot pass or will not work
When a wire cannot get past the blockage from below, or a tumor squeezes the ureter so hard that a stent will not drain, a nephrostomy goes around the problem.
- Too unwell for anesthesia
A nephrostomy can be placed with numbing medicine and light sedation, which can be safer for very sick people than general anesthesia.
- A urine leak
If the ureter or kidney is injured, diverting urine through a nephrostomy lets the leak heal.
- Kidney failure from blockage
When both kidneys or a single kidney are blocked, draining can bring kidney function back up.
- Access for stone surgery
Some hospitals place a nephrostomy before PCNL so the surgeon can use the same path.
Other options
- Ureteral stent
A tube placed from below through the bladder, sitting fully inside you with no bag. For a blocked, infected kidney from a stone it works about as well as a nephrostomy. It usually needs anesthesia, and stent symptoms are common.
- Treating the cause directly
When there is no infection and you are well enough, removing the stone may make a drain unnecessary.
- Antibiotics alone
Not safe for a blocked, infected kidney. Antibiotics cannot reach trapped infected urine well, so drainage is needed.
- Watching a blockage that is not infected
For some blockages without infection, with good kidney function and controlled pain, waiting a short time for a stone to pass may be reasonable.
Getting ready
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In an emergency
When it is planned
The day of
In the operating room, 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.
1. Lying face down
You lie on your front on a padded table in the interventional radiology room. Monitors track your heart, blood pressure and oxygen. Medicine through your IV makes you relaxed and drowsy.
After the operation
Right afterward
- Close watching
If you were placed for infection, nurses check your temperature, blood pressure and heart rate often. Some people need intensive care for a short time.
- Antibiotics
IV antibiotics continue, chosen based on the urine culture, then switch to pills.
- Measuring the urine
Urine output from the bag is measured. It is often bloody for the first day or two, then clears.
- Pain at the site
An ache where the tube enters is common for a few days. Pills usually control it.
- Learning tube care
Before you go home, a nurse teaches you or a family member how to empty and change the bag, care for the skin, and spot problems. Supplies and, often, home nurse visits are arranged.
At home
- The bag
Keep the bag below the level of your kidney so urine drains downhill. Empty it when it is about half full. Many people use a leg bag during the day and a larger bag at night.
- Securing the tube
Keep the tube taped to your skin in a gentle loop so a tug pulls on the tape, not the tube. Check that it is not kinked under clothing or when you sit or sleep.
- Dressing care
Change the dressing as often as your team advises, commonly 2 to 3 times a week and whenever it is wet or dirty. Wash your hands first, clean the skin as instructed, and look for redness, swelling or pus.
- Flushing
Some teams ask you to flush the tube with a small amount of sterile salt water; many do not. Flush only if you have been taught and told to.
- Showering
You can shower with the site covered by plastic wrap or a waterproof dressing. Avoid baths, swimming and hot tubs while the tube is in.
- Sleeping
Sleep on your back or on the side without the tube. Place the night bag on the floor or hang it on the bed frame below the mattress.
- Activity
Walking and daily tasks are fine. Avoid heavy lifting, twisting sports and anything that could pull on the tube.
- Drinking
Unless you are told to limit fluids, drink enough to keep the urine in the bag light yellow, about 2 liters a day for most people. This helps prevent blockage of the tube.
- Tube changes
If you need the tube for a long time, it is changed about every 2 to 3 months in the radiology department. This usually takes a few minutes with little discomfort.
- Driving
Wait until you are off opioid pain medicine and can turn comfortably. A small pad under the seat belt can protect the tube.
Recovery timeline
- Day 0Tube placed
Urine drains into the bag, often bloody at first. If you were very sick, fever and pain start to ease within hours to a day.
- Days 1 to 3Settling
Bleeding in the bag clears. Antibiotics continue. You learn how to care for the tube.
- Week 1Home with the tube
Most people are home, emptying the bag and changing dressings with help from family or a home nurse.
- Weeks 1 to 4Treating the cause
Once infection has cleared, the stone or other cause is treated, often with ureteroscopy or PCNL.
- Removal dayCapping trial and removal
The tube may be capped for 1 to 2 days to check that the kidney drains on its own. Then the tube is removed in a few seconds.
- 1 to 3 days after removalThe site seals
The opening may leak a little urine onto a gauze pad, then closes on its own.
- Every 2 to 3 monthsChanges for long-term tubes
If the cause cannot be fixed, the tube is exchanged on a schedule, or converted to an internal stent where possible.
What it feels like
Many people get a nephrostomy tube when they feel very sick, so the first memory is often relief. Living with a tube and bag takes adjustment, and most people find a routine within a week or two.
Arriving sick
Fever, shaking chills, vomiting and severe side pain. Fear is natural, especially when the team moves quickly.
What helpsAsk a family member to stay with you and to ask questions. The team will explain each step.
During the procedure
Lying face down can be uncomfortable. With sedation, most people feel the numbing sting, then pressure and pushing in the back, and remember little else.
What helpsTell the team if you feel pain or cannot breathe comfortably lying down. They can give more medicine or adjust padding.
The first hours
An ache at the site and red urine in the bag, which can look frightening. Many people feel their fever and side pain ease quickly as the kidney drains.
What helpsBlood in the bag is expected at first. Ask the nurse what to watch for.
Learning to live with the bag
Self-consciousness about the bag, worry about pulling the tube out, and trouble finding a comfortable sleeping position. Some people feel the tube limits intimacy and their sense of themselves.
What helpsLoose clothing and a leg bag under trousers make it less noticeable. Practice emptying and changing with the nurse until you feel confident. Talk openly with your partner.
Showering
Anxiety about getting the site wet the first time.
What helpsCover it well with plastic and tape, keep showers short, and change the dressing afterward if it gets damp.
Removal
A quick pulling feeling as the loop straightens and the tube slides out, then relief. A little leaking for a day or two can be surprising.
What helpsBreathe out slowly as it comes out. Keep gauze pads at home. Leaking that lessens each day is normal.
How well it works
Success means the kidney drains, infection clears, pain eases, and kidney function recovers as much as it can. The tube is a bridge until the cause is treated, or a long-term solution when it cannot be.
- Infection and fever clear
With drainage and antibiotics, fever usually settles within a day or two.
- Kidney blood tests improve
Creatinine, a blood marker of kidney function, often falls toward normal after drainage.
- Urine output in the bag
A steady flow means the tube is working. A sudden drop can mean a kink, a clot, or a moved tube.
- Checking drainage before removal
A capping trial or a dye study through the tube shows whether the ureter drains on its own before the tube comes out.
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
Usually clears within 1 to 2 days.
An ache for a few days, eased by pills.
Often means the tube is blocked or has moved. Call your team.
Redness under the dressing or tape, eased by careful skin care.
Less common
More likely the longer a tube stays. A tube that falls out needs attention the same day, because the path can close within hours.
Clots or debris can block the tube. It may need flushing or exchange.
Especially in people who were already infected. It usually responds to antibiotics but can be serious.
Bleeding that needs a blood transfusion or a procedure to seal a vessel from the inside (embolization). More likely in people with clotting problems or on blood thinners.
Rare
Air or fluid around the lung, or injury to the colon, spleen or liver. Very rare with image guidance.
A body-wide infection that needs intensive care, mostly in people who were very sick before the tube.
Call your care team or go to the emergency room if
- Fever of 101°F (38.3°C) or higher, or shaking chills
- The tube falls out or slips partly out (do not push it back in; call right away or go to the emergency room the same day)
- No urine in the bag for 2 hours or more, especially with back pain, after checking for kinks
- Urine leaking around the tube that soaks the dressing
- Bright red urine or clots in the bag that do not clear
- Redness, swelling, warmth or pus at the tube site
- Severe pain in your back or side
- Chest pain or shortness of breath (call 911)
Questions to ask your surgeon
- Why is a nephrostomy better than a stent for me?
- Who will place it, and will I be awake or asleep?
- How long will I need the tube?
- Who supplies bags, dressings and tape, and will a home nurse visit?
- How often should I change the dressing, and should I flush the tube?
- What should I do if it falls out at night or on a weekend?
- How often will the tube be changed if I need it long term?
- Can it be converted to an internal stent?
- What activities should I avoid?
- What is the plan to treat the cause of the blockage?
Words you may hear
- Nephrostomy
- An opening from the skin into the kidney. A nephrostomy tube drains urine through it.
- Percutaneous
- Through the skin.
- Interventional radiologist
- A doctor who performs procedures using imaging such as ultrasound, X-ray and CT to guide needles and tubes.
- Pigtail
- The curled, locking tip of the tube inside the kidney that keeps it from slipping out.
- Hydronephrosis
- Swelling of the kidney's drainage system from backed-up urine.
- Pyonephrosis
- Pus trapped in a blocked kidney. It needs urgent drainage.
- Sepsis
- A dangerous body-wide reaction to infection that can affect blood pressure and organs.
- Moderate sedation
- Medicine through the IV that makes you relaxed and drowsy while still breathing on your own.
- Capping trial
- Closing the tube for a day or two to see whether the kidney drains well on its own before removal.
- Nephrostogram
- An X-ray picture taken after dye is injected through the nephrostomy tube.
- Internalization
- Replacing an external nephrostomy tube with a stent that sits fully inside the body.
- Tube exchange
- Replacing a long-term tube over a wire with a new one, usually every few months.
Common questions
Should I have a nephrostomy or a stent?
For a blocked, infected kidney from a stone, both work about equally well. A nephrostomy can be done with light sedation and works when a stent cannot pass the blockage. A stent sits fully inside you with no bag. Your team picks what is fastest and safest for your situation.
How long will I have it?
It varies. After an infection from a stone, often a few weeks until the stone is treated. If a tumor or scar is blocking the ureter, it may be months, with tube changes every 2 to 3 months or conversion to an internal stent.
What if the tube falls out?
Cover the site with a clean dressing and call your team or go to the emergency room the same day. Do not try to push it back in. The path through the back starts to close within hours, so quick replacement is easier.
Can I sleep on that side?
It is better to sleep on your back or the other side, so you do not kink or pull the tube. A pillow behind your back helps you stay in position.
Does removal hurt?
Most people feel a brief pull for a few seconds. The site may leak a little urine for a day or two before sealing.
Can I have tubes in both kidneys?
Yes, if both kidneys are blocked. Each tube has its own bag, and care is the same for each.
Can I travel with a nephrostomy?
Yes, with planning. Carry extra bags, dressings and tape, a letter describing your tube, and the contact details of your team.
Sources this page draws on
- Society of Interventional Radiology, Quality Improvement Guidelines for Percutaneous Nephrostomy
- American Urological Association and Endourological Society, Surgical Management of Stones: AUA/Endourological Society Guideline (2016)
- European Association of Urology, EAU Guidelines on Urolithiasis
- Journal of Urology, Optimal method of urgent decompression of the collecting system for obstruction and infection due to ureteral calculi (1998)
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Kidney Stones
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.