Pathophysiology

Calcium oxalate or phosphate kidney stones(80%)

They are caused by oversaturation of calcium and oxalate/phosphate in urine. They are called Mulberry Stone covered with sharp Projections (and hence hematuria). They are always associated with conditions causing hypercalcaemia.

Uric acid kidney stones(9%)

They result from higher levels of purines(compounds used to make building blocks of DNA/RNA highly found in meat products and later broken down into uric acid). They are formed in low pH urine (acidic urine) hence conditions associated with impaired renal ammoniogenesis, such as metabolic syndrome and type 2 diabetes must be ruled in/out.

Struvite kidney stones(10%)

They contain ammonium, magnesium, and calcium binding with phosphate (triple phosphate). They are associated with infection by urease-producing microorganisms, such as Proteus mirabilis, Klebsiella pneumonia, Staphylococcus aureus, Pseudomonas aeruginosa, Providencia stuartii, Serratia, and Morganella morganii.

Cystine kidney stones(1%)

They are due to an inherited defect in the transport of the amino acid cystine, leading to excessive excretion in the kidney, causing cystinuria. When Cystine supersaturates in the kidney results into crystal formation.