How Long Does It Take To Pass A Kidney Stone? Experts Weigh In

Kidney stones can be as painful as childbirth. This has been explored in multiple studies. Have you wondered what makes them so painful? It is mainly because of the way they pass through your body and out. So how long does it take for kidney stones to pass via urine? This depends on various factors. Today, we will tell you all about it. 

To get a better understanding of this, the editorial team of OnlyMyHealth reached out to experts, Dr Sanjeev Gulati, Chairman, Nephrology, Fortis Escorts  Okhla, New Delhi and Dr Smriti Singh, Associate Consultant, Nephrologist, Narayana Hospital Gurugram.

How Long Does It Take To Pass A Kidney Stone? 

Let us start by addressing the main question: what is the average time taken to pass a kidney stone? “There is no specific time frame for this. The passage depends on size, hydration status, and location of the stone. Stones that are less than 4 mm pass naturally in 80 to 90% of cases, while 5 to 7 mm stones have a 60% to 80% chance of passage, and more than 8 mm stones have less than 10% chance of passage. Calyceal stones pass more easily as compared to upper ureteric and lower calyceal stones,” answers Dr Singh.

As per the National Health Service (NHS), small kidney stones may cause pain until they are passed through urine. This may take a few weeks. On this note, NHS shares tips to ease your symptoms (under medical professional’s guidance):

• Drink plenty of fluids throughout the day.
• Take anti-sickness medicine.
• Take alpha-blockers (medicines to help stones pass).

The report further mentioned that one should make sure they are drinking enough fluid. If urine is dark, it means one is not drinking enough water; urine colour should be pale. If kidney stones are too big to be passed naturally, they are generally removed by surgery. As per NHS, the main types of surgery for removing kidney stones are:

• Shockwave lithotripsy (SWL).
• Ureteroscopy.
• Percutaneous nephrolithotomy (PCNL).

However, the type of surgery will depend on the size and location of the stones.

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How Quickly Can You Flush Out A Kidney Stone?

According to the National Institute of Health (NIH), the time it takes for a kidney stone to pass can vary, depending on the stone size. It mentions that small kidney stones are generally passed with the urine after one or two weeks; the ones that are not flushed on their own within four weeks are usually treated. 

Shedding light on how quickly can you flush out a stone, Dr Gulati shares some tips for the same, “Drink two to three litres water daily (clear urine goal), add lemon juice for citrate, stay lightly active, and use prescribed alpha-blockers (such as tamsulosin) to relax the ureter. Small stones may pass in days to weeks, but there is no guaranteed time.” Dr Singh says, “Medical expulsive therapy by drugs and transfusion helps easy passage of small non-obstructing stones.”

How Do You Know When You Pass A Kidney Stone?

Is there a way to understand when you pass a kidney stone via urine? “You can understand this if you experience sudden pain relief, plus see a small stone/grit in urine (strain it) or resume normal urination,” says Dr Gulati.

Adding to this, Dr Singh shares: “Pain subsides sharply after colicky episodes peak. Urine shows blood streaks or gritty particles, confirmed by a straining sample. Follow-up ultrasound reveals empty tract, no hydronephrosis. Symptom relief includes better urination flow. Stone capture aids analysis for recurrence prevention, standard in Indian clinics. Repeat imaging verifies clearance within 48 hours.”

What Are The 4 Stages Of Passing A Kidney Stone?

From formation to passing through urine: kidney stones have quite a journey inside the human body. According to Harvard Health, first, stones form in the kidneys, then they can dislodge and pass down the ureter, which is the tube that connects the kidneys to the bladder, blocking the flow of urine. This phase causes severe pain, sometimes with blood in the urine, nausea, and vomiting. 

Then the stones pass down the ureter toward the bladder: this phase leads to frequent urination, bladder pressure, or pain in the groin. Once the stone moves out of the ureter and enters the bladder, the pain generally subsides almost immediately. From there, the stone typically passes out of the body quickly via urine. Now let us hear it out from our expert about the 4 stages of passing a kidney stone.

Dr Singh summarises the stages for better understanding:

• Stage one involves lodging in the ureteropelvic junction, causing initial flank pain and nausea.
• Stage two sees ureteric transit with colic waves as stone moves downward.
• Stage three brings bladder arrival, frequency and urgency dominate.
• Stage four completes urethral passage, marked by terminal burning and particle voiding. Each stage varies by size; hydration eases progression per Indian guidelines.

When To Visit A Doctor For Kidney Stones?

If you find a stone in your abdominal scan, you should always visit a doctor who can guide you regarding further lines of treatment. “Stones that obstruct the ureter and are difficult to pass spontaneously, causing pain in the flanks, loin to groin pain, blood in urine, recurrent urinary tract infection, and need removal, which can be achieved by advanced education, minimally invasive, or non-invasive procedures,” says Dr Singh. “Seek immediate care for severe/unmanageable pain, fever/chills, vomiting (can’t keep fluids), inability to urinate, or blood in urine. Follow up if there is no passage after four to six weeks,” adds Dr Gulati.

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The Final Word

There is no specific time that kidney stones take to pass. This depends entirely on size, hydration status, and location of the stone. Small kidney stones are usually passed with urine within one or two weeks; while big ones that are not flushed on their own within four weeks are usually treated. Consult a doctor and do follow-ups to understand the status of your stones and take proper medical treatment.