From the web site of The British Association of Urological Surgeons Ltd who write, "Kidney stones are found in 2%-3% of people and 0.5% of people present each year with an acute episode of pain due to stones; these rates have been rising steadily since the start of the 20th century.
Men are more commonly affected than women. After the age of 50 then the sex distribution becomes equal;
At the age of 70, you have a lifetime risk of 1 in 8 for forming a stone;
Stones are responsible for more than 12000 hospital admissions each year;
Stone formation is governed by both intrinsic (heredity, age and sex) and extrinsic factors (geography, climate, water intake and diet);
Poor fluid intake combined with low-roughage, high protein diet containing a lot of refined sugar increases the risk of stones.
There is an association with the "metabolic syndrome" (Syndrome X)
Recurrence rates for stones are high (20% at 5 years, 35% at 10 years and 70% at 20 years)