Uric Acid Stones
Uric acid stones are the great example of a stone you can dissolve with a pill — because their formation is driven by one dominant, correctable factor: acidic urine.
The big picture
Uric acid stones are the great example of a stone you can dissolve with a pill — because, almost uniquely, their formation is driven by one dominant, correctable factor: acidic urine. Understand that and the whole topic follows: they form when urine is too acidic, they are invisible on plain film (radiolucent), and alkalinising the urine both dissolves existing stones and prevents new ones. No other common stone is so medically treatable.
The framework: uric acid stones form in persistently acidic, concentrated urine, are radiolucent, associate with gout / high cell turnover / metabolic syndrome, and are dissolvable by urinary alkalinisation.
Mechanism pathway
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Diagnostic algorithm
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Board traps
Acidic urine (low pH) is the master factor — pH is the lever, not just uric acid load.
Radiolucent on plain film, low HU on CT — easily missed on KUB.
Alkalinisation (potassium citrate) can dissolve uric acid stones — a stone you treat with a pill.
Associations: gout, myeloproliferative/high-turnover states, metabolic syndrome/diabetes (low urine pH from impaired ammonium excretion).
Allopurinol for overproduction; alkalinisation for the pH.