Types of Kidney Stones

Kidney stones are grouped mainly by what they are made of. The type guides prevention.

Calcium stones (about 8 in 10)

• Calcium oxalate: the most common type. Linked with low fluid intake, high salt, high oxalate intake and low urine citrate.
• Calcium phosphate: linked with high urine pH, hyperparathyroidism and some kidney conditions.

Uric acid stones

Form in very acidic urine. Linked with gout, high intake of animal protein, obesity, diabetes and dehydration. They can sometimes be dissolved with medicines that make the urine less acidic.

Struvite (infection) stones

Form after urinary infections caused by certain bacteria. They can grow quickly and fill the kidney (staghorn stones). They often need procedural removal.

Cystine stones

Rare inherited stones from cystinuria. They tend to recur, begin young and need long-term care.

Other types

Stones from some medicines, such as certain protease inhibitors.

By size and location

• Small stones under 5 mm often pass on their own
• Stones 5 to 10 mm may pass or may need help
• Larger stones usually need treatment
• Location: in the kidney, ureter, bladder or urethra

Ayurvedic grouping

Ayurveda describes ashmari by dosha, such as Vataja, Pittaja, Kaphaja and Shukraja. These are traditional types that do not map to the chemical types above.

Key point

Stone analysis, when a stone is caught, tells the doctor what to change to prevent the next one.

Before your appointment

Note when the pain began, where it is, and whether you have noticed blood, fever, nausea or burning in your urine. Record how much you drink and pass urine in a day. List medicines and supplements, especially vitamin C, vitamin D, calcium and herbal products. Mention previous stones, gout, bowel surgery, urinary infections and family history. Bring earlier scans and reports. If you pass a stone, save it for analysis. Ask about tests, the stone type and a prevention plan. Call 112 for fever with pain or if you pass no urine.