Kidney stones (also called renal calculi) are hard mineral deposits that form inside your kidney. They can cause sudden, severe pain as they try to pass through your urinary system, but most pass on their own with time, fluids and pain relief.
Emergency
Call triple zero (000) for an ambulance or go to your nearest emergency department if you have kidney stone pain and:
- fever, chills or feeling generally unwell with your pain (this can mean an infected, blocked kidney, which requires urgent medical attention)
- you cannot pass any urine at all
- your pain is not controlled by simple pain relief
- you keep vomiting and cannot keep fluids down
- you only have one kidney or have had a kidney transplant and you develop new back, side or abdominal pain
Key points
- Kidney stones are hard crystal deposits that form in your kidney, most often made of calcium oxalate.
- The classic symptom is sudden, severe pain in the side of your body, between your lowest ribs and your hip. It comes in waves and can spread to your groin and abdomen.
- Dehydration is one of the biggest and most fixable risk factors, alongside diet, family history and some medical conditions.
- Most small stones pass by themselves within a few weeks with fluids and pain relief.
- Larger or stuck stones may need a procedure such as shockwave treatment or a camera examination of the urinary system.
- A first severe episode needs same-day in-person assessment, usually with a scan or x-ray, to confirm the diagnosis and rule out other causes.
What are kidney stones?
Kidney stones are hard clumps of crystals that form inside your kidney. Your kidneys filter your blood and produce urine. When there is too much of certain chemicals, or not enough fluid to keep them dissolved, they can clump together into a solid stone.
Most kidney stones in Australia are made of calcium oxalate. Less common types include calcium phosphate stones, uric acid stones, and rarer struvite and cystine stones. The type matters because it affects how a stone is treated and how you can reduce your chance of getting another one.
Kidney stones are common, affecting around 4 to 8 in every 100 Australians at some point in their life. They affect men more often than women, although that gap has been narrowing. Many people who get one stone will get another. Some stones stay in the kidney and cause no problems at all. Others move into the ureter, the narrow tube that carries urine from your kidney to your bladder, where they can cause intense pain and sometimes block the flow of urine.
Kidney stones can affect anyone, but they become more likely with age, certain diets, and if you have had one before.
Symptoms of kidney stones
The classic symptom of a kidney stone is sudden, severe pain. Doctors call this renal colic. It can start in your side, and can spread around to the front of your abdomen or groin.
This pain has a distinctive pattern. It tends to come in waves rather than staying constant, easing off for a while before coming back. As a result, people with a kidney stone often cannot find a comfortable position, preferring to pace rather than sit still.
Along with the pain, you might notice:
- nausea or vomiting
- blood in your urine, which can be visible or only picked up on a test
- a frequent or urgent need to pass urine
- pain that spreads to your groin or genitals
Some people have no symptoms at all, especially if the stone stays in the kidney and does not move. These stones are sometimes found by chance on a scan completed for another reason.
Not everyone experiences a kidney stone the same way. Smaller stones can cause milder, grumbling discomfort, while a stone stuck in the ureter can trigger severe pain. If the stone sits at the point where the ureter enters the bladder, you might feel a constant urge to urinate even when your bladder is almost empty.
Symptoms that need urgent care
Most kidney stone pain, however severe, can be managed with regular pain relief while waiting for the stone to pass. However, some symptoms mean you need urgent assessment and consideration of other treatments as they suggest a complication.
Fever or chills with your pain are important warning signs. This can mean an infection has developed behind a blocked kidney, which needs urgent assessment and treatment with antibiotics. Left untreated, this can lead to overwhelming infection (sepsis), which can be life-threatening.
Inability to pass urine is also a red flag, as is pain that simple over-the-counter pain relief does not help. Persistent vomiting can also be a problem as it leads to dehydration and means you are not able to take pain relief effectively. If you have only one working kidney, or you have a kidney transplant, any new episode of back, side or abdominal pain needs prompt attention. This is because there is no backup kidney to compensate if your primary one becomes blocked.
If any of these apply to you, call triple zero (000) or go to your nearest emergency department. Do not wait to see if the pain settles on its own.
When to see a doctor
If you get sudden, severe pain in your back, side, abdomen or groin that comes in waves, it is worth getting checked.
Call triple zero (000) or go to your nearest emergency department if:
- you have fever, chills or feel generally unwell with your pain
- you cannot pass urine at all
- your pain is not controlled by simple pain relief
- you are vomiting repeatedly and cannot keep fluids down
- you have a single kidney or a kidney transplant and develop new back, side or abdominal pain
See a doctor the same day, in person, if this is your first severe episode of this kind of pain. The first time you have suspected kidney stone pain, you need to be assessed in person, usually in an emergency department. Your doctor will need to examine you and arrange a scan or x-ray depending on their findings. This will help confirm whether you actually have a kidney stone and help to rule out other causes of severe abdominal or back pain. This is not something a telehealth consultation can safely do on its own. Same-day assessment is especially important if you are pregnant, or if you are over 50 and have never had a kidney stone before, because other serious conditions, such as a problem with the main blood vessel in your abdomen (the aorta), can cause similar pain.
See your GP within a few days if you develop blood in your urine, even if the pain has settled. Blood in the urine can have other causes that need checking.
Book a routine GP appointment if you have milder, ongoing discomfort or you want to discuss prevention after a previous stone.
A GP or telehealth appointment is appropriate once a stone has already been diagnosed and you are not in an emergency. This includes follow-up after treatment, discussing results of blood or urine tests, getting advice on preventing future stones, and organising a medical certificate if you need time off work or study while you recover.
It is always reasonable to get checked "just in case." Doctors would rather see you early for reassurance, regardless of the ultimate diagnosis.
Causes & risk factors
What causes kidney stones?
A kidney stone forms when your urine contains high levels of stone-forming chemicals, like calcium, oxalate or uric acid, and not enough fluid to keep them dissolved. These chemicals clump together into crystals, which grow into a solid stone over time. Sometimes stones form even when these chemicals are at normal levels, which is why some people get stones and others with a similar diet do not.
Most stones in Australia are calcium oxalate stones. Uric acid stones are often linked to a diet very high in meat and protein. Struvite stones form because of urinary tract infections, and can grow surprisingly large. Cystine stones are rare and run in families, caused by an inherited condition that affects how your kidneys handle a particular amino acid.
Risk factors for kidney stones
Dehydration is one of the biggest risk factors for kidney stones, and it is also one of the easiest to change. If you do not drink enough fluid, your urine becomes more concentrated, which makes it easier for crystals to form. People who live in hot climates, work outdoors, or exercise heavily without replacing fluids are at higher risk for this reason.
Diet plays a real role too. A diet high in salt and animal protein increases the amount of calcium and uric acid your kidneys need to get rid of in your urine, raising your risk.
Family history matters. If a parent or sibling has had kidney stones, you are more likely to get one yourself. Having had a kidney stone before is one of the strongest predictors of getting another. In one large study, about one in five people had another painful stone within five years of their first, and around a third had new stones show up on scans.
Some medical conditions increase your risk, including inflammatory bowel disease, some digestive tract diseases, an overactive parathyroid gland, and being significantly overweight. Certain medicines can also raise your risk, including topiramate (used for epilepsy and migraine), some HIV medicines and high-dose vitamin C supplements. Your doctor can tell you if anything you are taking puts you in this category.
How kidney stones are diagnosed
If you see a doctor with sudden, severe abdominal, back or side pain, your doctor will start by asking about your symptoms and examining your abdomen and back. Your doctor may ask what your pain feels like, whether it comes in waves, if you have noticed blood in your urine, and whether you have had fevers or chills. These questions help distinguish a kidney stone from other causes of abdominal pain that need different treatment. They will usually ask you to give a urine sample for a urine dipstick test. This test can pick up blood, which is present in most people with a kidney stone, and can also flag signs of infection.
The first time you have suspected kidney stone pain, a scan is often needed to help confirm the diagnosis. This may be a CT scan or an ultrasound, depending on your age, symptoms and other risk factors. Your doctor will decide which is best for you. This is sometimes combined with a plain x-ray, as about half of stones show up on this type of imaging, which can help track a stone on follow-up without needing another scan.
Blood tests are usually taken to check your kidney function and calcium level. If you have passed a stone, or catch one in a urine strainer, bringing it to your doctor lets it be sent off for analysis, which helps work out what type of stone it is and how best to prevent another one.
Treatment for kidney stones
Pain relief and watchful waiting
Most kidney stones, especially small ones, pass on their own within a few weeks. While this happens, treatment focuses on controlling pain and keeping you comfortable. Anti-inflammatory pain relief is usually the most effective option for kidney stone pain, and your doctor can advise on what is suitable and safe for you. If pain is severe, you may need stronger pain relief for a short time, sometimes requiring a brief hospital stay.
Drinking plenty of clear fluids helps keep things moving, though it will not necessarily speed up passage of a stone that is already stuck. Your doctor may ask you to strain your urine through a fine sieve so any stone that passes can be caught and sent for analysis.
Medicines to help stones pass
For some stones in the ureter, your doctor may prescribe a medicine that relaxes the muscle in the ureter wall, making it easier for the stone to pass. The evidence for this is mixed: some studies show a real benefit, particularly for stones closer to the bladder, while at least one large trial found little difference. It does not work for everyone, and your doctor will explain whether it is likely to help in your situation.
When a procedure is needed
Larger stones, or stones that do not pass after a reasonable period of waiting with pain relief and fluids, may need a procedure. The right option depends on the size, number and location of your stones. If you need a procedure, you will be referred to a urologist, a specialist surgeon who manages conditions of the urinary tract.
Shockwave lithotripsy uses focused sound waves from outside your body to break a stone into smaller fragments that can then pass in your urine. It is generally used for smaller stones sitting within the kidney.
Ureteroscopy involves passing a thin telescope up through your urinary system, then under direct vision a laser can be used to break up the stones. This is the most commonly used procedure for stones anywhere in the urinary tract and can treat most stones under about 20mm. A small stent (a thin, soft tube) is often left in the ureter for a short time afterwards to help things heal and drain.
For very large stones, or those sitting deep in the kidney, a urologist may recommend percutaneous nephrolithotomy, a surgery to access the kidney directly and remove the stone.
If a stone is blocking your kidney and you are unwell or in severe pain, you may need urgent hospital treatment to drain the kidney, sometimes with a temporary tube, before the stone itself is dealt with.
Self-care & living with kidney stones
While you are waiting for a stone to pass, keep drinking water throughout the day rather than large amounts all at once. Aim for urine that looks pale rather than dark. Take pain relief as your doctor has advised, and do not wait until pain becomes unbearable before using it, since staying ahead of the pain generally works better than chasing it.
It helps to know what an episode of kidney stone pain usually feels like, so you can tell the difference between expected waves of pain and a new, worrying symptom like fever. Keep a note of when your pain started and what seems to ease or worsen it. This is useful information for your doctor.
Straining your urine through a fine sieve or piece of cloth for a few days can help you catch a stone if it passes, which is useful for prevention planning later. Some people find it reassuring to actually see the stone; it can turn an invisible problem into something concrete they have dealt with.
Kidney stone pain can be frightening as well as painful, and it is common to feel anxious about it happening again, particularly if you have had more than one episode. Talking to your doctor about a plan for future episodes, including what pain relief to keep on hand, can take some of the fear out of it. If you need time off work while you recover, your doctor can provide a medical certificate.
Complications & outlook
Most kidney stones cause a painful few weeks and then resolve without lasting harm. The main risk is if a stone blocks the flow of urine out of the kidney and this is not treated. Left untreated, this can damage the kidney over time.
The most serious complication is infection developing behind a blocked kidney. This combination of obstruction and infection can lead to overwhelming, body-wide infection that requires urgent care.
Repeated stones can, over years, contribute to scarring in the ureter or kidney, particularly in people who keep forming stones throughout their life. This is one reason doctors are keen to identify the type of stone and tailor prevention after a first episode, rather than simply treating each stone as it comes.
For most people, the outlook after a kidney stone is good. Once the stone has passed or been removed, kidney function usually returns to normal, and with some attention to fluids and diet, many people go years without another episode.
Can kidney stones be prevented?
Fluid intake is the single most important thing you can change to reduce your risk of kidney stones. Drinking enough throughout the day, so your urine stays pale rather than dark, dilutes the chemicals that form stones and has been shown in good quality research to lower the chance of getting another one.
Diet matters too, though not always in the way people expect. Cutting back on salt is useful, since a high-salt diet increases the amount of calcium your kidneys need to remove, which raises stone risk. Reducing animal protein, particularly if you eat a lot of meat, can also help, especially for uric acid stones. Contrary to a common myth, cutting dietary calcium is not the answer for most people; a normal calcium intake from food actually helps prevent calcium oxalate stones, because calcium binds to oxalate in your gut before it reaches your kidneys. Restricting calcium is really only advised for specific situations, and your doctor or a dietitian can tell you if this applies to you.
If you have had a stone before, it is worth having it analysed and having some follow-up blood and urine tests. These can identify the type of stone you form and whether an underlying condition is contributing, which lets your doctor give you advice tailored to your situation rather than generic tips. Some people are prescribed a specific medicine long-term to reduce further stone formation, depending on the results.
Maintaining a healthy body weight and treating urinary infections promptly also reduce your risk. None of this guarantees you will never get another stone, but each of these changes lowers the odds.
How Doccy doctors can help
A Doccy consultation is done with our voice AI agent, through our platform and over the phone, so it is not suitable for a first episode of severe back, side or abdominal pain, or for any of the warning signs above. These need in-person assessment, usually in an emergency department, where a doctor can examine you and arrange a scan.
Once a stone has been diagnosed and you are recovering, a Doccy doctor can:
- provide a medical certificate if you need time off work or study, including multi-day certificates for longer recoveries
- provide a carer's certificate if you are looking after someone with a kidney stone
- arrange a specialist referral to a urologist if you have had more than one stone or your doctor thinks specialist review would help
For follow-up tests, results and a long-term prevention plan, your regular GP is the best place to start.
Resources & support
- healthdirect: Free, government-funded health information and a 24-hour helpline on 1800 022 222 for advice on kidney stones and other conditions.
- Kidney Health Australia: Information on kidney stones and other kidney conditions, plus a free Kidney Helpline on 1800 454 363.
- Better Health Channel (Victoria): Practical information on kidney stone types, treatment and prevention.
These resources can provide extra information, but they do not replace advice from your own doctor.
- healthdirect. Kidney stones. 2024. https://www.healthdirect.gov.au/kidney-stones
- Better Health Channel (Victoria), produced with Kidney Health Australia. Kidney stones. 2022. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/kidney-stones
- Kidney Health Australia. Kidney stones. 2026. https://kidney.org.au/your-kidneys/what-is-kidney-disease/types-of-kidney-disease/kidney-stones
- Tunnicliffe DJ, Lloyd L, Mullan A, et al. Prevention of recurrent kidney stones: A CARI Guidelines summary. Kidney International Reports. 2026. https://pubmed.ncbi.nlm.nih.gov/41858317/
- European Association of Urology. EAU Guidelines on Urolithiasis. 2025. https://d56bochluxqnz.cloudfront.net/documents/full-guideline/EAU-Guidelines-on-Urolithiasis-2025.pdf
- Sewell J, Shoshany O, Katz DJ, Love C. Urolithiasis – Ten things every general practitioner should know. Australian Family Physician. 2017. https://www.racgp.org.au/afp/2017/september/urolithiasis
- Romero V, Akpinar H, Assimos DG. Kidney stones: A global picture of prevalence, incidence, and associated risk factors. Reviews in Urology. 2010. https://pubmed.ncbi.nlm.nih.gov/20811557/
- Lin BB, Lin ME, Huang RH, Hong YK, Lin BL, He XJ. Dietary and lifestyle factors for primary prevention of nephrolithiasis: a systematic review and meta-analysis. BMC Nephrology. 2020. https://pubmed.ncbi.nlm.nih.gov/32652950/
- D'Costa MR, Haley WE, Mara KC, et al. Symptomatic and radiographic manifestations of kidney stone recurrence and their prediction by risk factors: A prospective cohort study. Journal of the American Society of Nephrology. 2019. https://pubmed.ncbi.nlm.nih.gov/31175141/
- Sharma G, Pareek T, Kaundal P, et al. Comparison of efficacy of three commonly used alpha-blockers as medical expulsive therapy for distal ureter stones: A systematic review and network meta-analysis. International Braz J Urol. 2022. https://pubmed.ncbi.nlm.nih.gov/34003612/
- Pickard R, Starr K, MacLennan G, et al. Medical expulsive therapy in adults with ureteric colic: A multicentre, randomised, placebo-controlled trial. Lancet. 2015. https://pubmed.ncbi.nlm.nih.gov/25998582/
- Curhan GC, Willett WC, Rimm EB, Stampfer MJ. A prospective study of dietary calcium and other nutrients and the risk of symptomatic kidney stones. New England Journal of Medicine. 1993. https://pubmed.ncbi.nlm.nih.gov/8441427/
- Heilberg IP, Goldfarb DS. Optimum nutrition for kidney stone disease. Advances in Chronic Kidney Disease. 2013. https://pubmed.ncbi.nlm.nih.gov/23439376/
- Pearle MS, Matlaga BR, Antonelli JA, et al. Surgical Management of Kidney and Ureteral Stones: AUA Guideline (2026). Part II: Evaluation and Treatment of Patients With Kidney and/or Ureteral Stones. Journal of Urology. 2025. https://pubmed.ncbi.nlm.nih.gov/41263322/