Urinary tract calculi

Keywords: Renal calculi, Renal stone, Calculus

Causes

Appropriate Tests

 

Investigation is usually only indicated in those patients with recurrent calculi.

MCS urine; early morning specimen for pH (to assess predisposition for uric acid crystals);

Urine: Calcium urine, Phosphate urine, Urate urine, Creatinine urine, Electrolytes urine.

Calculus analysis, if specimen available.

Plasma: Creatinine, Urea, Urate, Calcium, Phosphate, Protein (total), Albumin; Full blood count, Blood film.

Calcium stones

Stones may have a uric acid nidus.

Hypercalciuria, especially

  • Familial
  • Hypercalcaemia

 

Hyperoxaluria

Oxalate urine.

Renal tubular acidosis

 

Idiopathic

 

Uric acid stones

 

Hyperuricaemia, especially

  • Hyperuricosuria

 

Dehydration

 

Struvite stones

 

Urinary tract infection

 

Cystine stones

 

Cystinuria

Amino acids urine.

Xanthine stones

 

Xanthinuria

Xanthine urine - consult pathologist.

Allopurinol

 

Factitious stones

Usually insoluble in acid.