Does Every Kidney Stone Need Treating?

Dernière mise à jour : 15 août 2026

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One of the commonest conversations in my office starts with a health-check report: a kidney stone, found by chance, in someone with no symptoms at all. The assumption that follows is almost always the same — that it has to come out. Often it does not, and sometimes there is no stone there to begin with.

First: is it really a stone?

Health-check packages use ultrasound, and for good reasons — it is quick, inexpensive and involves no radiation. But it is a screening tool, and screening tools are built to avoid missing things rather than to be precise.

Where ultrasound falls short

1. It depends on the operator. Accuracy varies considerably with the experience of the person holding the probe.
2. It overcalls small stones. Its accuracy for small stones is only around 45%, and calcified blood vessels or calcification within kidney tissue can look very like a stone. A good number of people are told they have one when they do not.
3. It struggles in larger patients. Thick tissue degrades the image and the reliability with it.

Where the finding needs confirming, the gold standard is a non-contrast CT: around 95% accurate, able to detect stones as small as 1.25 mm, and able to tell you exactly how big the stone is and where it sits — which is what actually decides the management. Modern low-dose stone protocols use radiation far below any level of concern.

Why 4 mm is the number that matters

No — not every stone needs removing. The narrowest part of the urinary tract is the ureter, and a stone of 4 mm or smaller has a good chance of passing through it on its own, often without severe pain. Below that size, watchful observation is a legitimate plan, not a delay tactic: there is no benefit in an expensive procedure for a stone that would have left by itself.

The practical measure while you wait is fluid. Drinking more than 2.5 litres of still water a day produces enough urine to help move a small stone along. And since the stone that formed once tends to be followed by another, this is also the point at which looking at why it formed is worth the effort.

When a stone stops being a wait-and-see problem

Watchful waiting assumes you stay well while you wait. Seek urgent medical care rather than waiting if you develop a fever alongside stone pain — fever with an obstructing stone means an infected, blocked kidney, which is a genuine emergency and needs drainage promptly, not antibiotics alone. The same applies if the pain is severe and unrelieved, if you are vomiting and unable to keep fluids down, or if you stop passing urine altogether.

Short of that, treatment is considered when the stone is larger than 4–6 mm and unlikely to pass, when it obstructs the flow, when the pain keeps recurring, or when you have only one working kidney. Shockwave lithotripsy et chirurgie des calculs au laser are the two routes then, chosen on the stone’s size, position and hardness.

The message worth taking away is that a stone on a checkup report is a finding, not a verdict. It deserves a proper look — sometimes to confirm it is really there, usually to measure it, and often to conclude that nothing needs doing at all.

Si une calculs rénaux a été détecté lors de votre bilan de santé et que vous souhaitez une évaluation urologique approfondie, le Dr Soarawee Weerasopone propose des consultations spécialisées au siège de l'hôpital de Bangkok. Prendre rendez-vous. Les rendez-vous à l'hôpital Samitivej Sriracha peuvent être pris en appelant le service d'urologie au 088-022-1445.

Foire aux questions sur le traitement des calculs rénaux

Avis de non-responsabilité : This content is written and reviewed by Dr. Soarawee Weerasopone, a board-certified urologist at Bangkok Hospital Headquarters. It is intended for educational purposes only and does not constitute medical advice. No medical advice, diagnosis or prescription is provided through personal messaging channels. Always consult a qualified healthcare professional before starting any medical treatment.