Conditions & Treatments

Urinary Stones (Kidney Stones) - Causes and Risk Factors

Why do Kidney Stones occur?

Kidney stones occur when certain salts and minerals are present in excessive concentrations in the urine, and these eventually precipitate into small crystals that accumulate into stones. There is no single definite cause for the formation of stones, but is more likely due to several contributing factors that increase the risk of stone formation.

Risk Factors

Age: Usually more common in older individuals ~40 – 60 years of age.
Obesity: Has been associated with >50% higher risk of stone formation.
Genetic: A history of kidney stones within the family is associated with a higher risk.
Dehydration: A lack of fluid intake leads to concentration of salts in the urine, increasing risk of stone formation.
Diet: Certain diets high in oxalate (nuts, long beans, chocolate), high in purines (red meat, organs, seafood).
Previous kidney stones: An individual with a diagnosed kidney stone has a 50% risk of developing another stone within the next 10 years.
Certain medical conditions: Diabetes, metabolic syndrome, hyperparathyroidism, renal tubular acidosis, gastrointestinal diseases (including inflammatory bowel disease, malabsorption, bariatric surgery, previous intestinal resections). Known conditions associated with urinary tract obstruction can also increase the risk of stone formation.
Use of certain medications: HIV medications (indinavir).

When to see a doctor

It is pertinent to seek medical attention when complications of kidney stones arise, and these can include:

Severe pain, not responding to painkillers
High fever, with temperature >38°C. Infections that occur when urine is obstructed in the urinary system can be severe and life-threatening, and immediate medical attention is crucial.
Visible haematuria (blood in the urine)
Symptoms of renal failure: Severe shortness of breath, swelling of both legs