Altered colloid-crystalloid ratio leads to precipitation of crystals in urine, which stick together and can grow into a "stone". Smaller ones get excreted through urine but a large calculus can obstruct urine flow or can irritate the urinary tract mucus. Small Calculi are usually asymptomatic but, at times, can cause dysuria, oliguria and haematuria. There may be nausea, vomiting, fever with chillness, weakness, cloudy or foul smelling urine and infection due to urinary obstruction.

Urinary tract infections (UTL's) second only to respiratory infections in frequency, account for 10 million visits to the doctor each year. It is evident in both men and women in equal ratio.