Your Health A-Z

Kidney stones:
who is at risk?

A Mediclinic urologist explains how lifestyle choices in South Africa are causing a higher incidence of kidney stones in children – and who else is at risk.

When you consider that 1 500 litres of blood pass through your kidneys every day, it’s no surprise that sometimes things can go awry. And if we are unkind to our kidneys, small crystals – kidney stones – can form and get lodged in the ureters, the tubes leading from the kidneys to the bladder. Not only are kidney stones painful, they can also grow and obstruct urine drainage, causing infections such as bladder infections, and in extreme cases septic shock or kidney failure. Here’s how to treat and prevent kidney stones. 

The causes

There are four different types of kidney stones – made largely from either phosphates, uric acid, amino acids, or most commonly calcium. Dr Preena Sivsankar, a urologist at Mediclinic Vereeniging, says lack of exercise resulting in a high body mass index and a diet high in animal protein, dairy products and refined sugar are often the cause of kidney stones. In fact, vegetarians have a 40-60% lower risk of developing kidney stones than meat-eaters. She also notes that because of poor lifestyle choices there is a worrying trend of a higher incidence of kidney stones in children.

As a general rule, those most at risk include 30- to 69-year-old caucasian men, and people living in hot, dry climates. The reason for this is that their urine becomes more concentrated as they sweat more. Keeping urine diluted by drinking water instead of concentrated beverages is one way to reduce this risk.

How to treat kidney stones

Surgery is not always necessary. ‘Antibiotics can be used to reduce the number of bacteria in the urinary tract, or thin stents may be placed endoscopically to relieve the blockage and infection caused by the stone,’ says Dr Sivsankar. However, if the infection is only treated with antibiotics, there is a risk of future infections and antibiotic-resistant bacteria.

Dr Sivsankar says small stones (less than 5mm) usually pass by themselves during urination with increased fluid intake and pain medication, and soft stones can be dissolved by altering the pH of urine with orange juice for example. Orange juice, as well as lemon juice, asparagus and black cherries, can reduce the levels of uric acid and calcium in urine, possibly preventing and reducing the recurrence of certain types of kidney stones.

‘Treatment is recommended based on the size, position and hardness of the stones. Laser and extracorporeal shock wave lithotripsy (ESWL) therapies, used for stones less than 1cm, are minimally invasive and don’t require any incisions. For larger stones, the best is laparoscopic surgery or percutaneous nephrolithotomy (removing the stones via small incisions or a puncture wound).’

How to prevent kidney stones

  • Drink at least two litres of water a day to keep urine as clear as possible
  • Eat less animal protein, especially dairy and red meat
  • Reduce salt consumption
  • Cut down on sugar
  • Cut down on tea, coffee and soft drinks
  • Cut down on alcohol
  • Don’t smoke (cadmium in cigarettes is poisonous to your kidneys)
  • Control your weight and be active
  • Regular skin brushing and lymph drainage massages could also help to remove toxins

In the interest of our patients, in accordance with SA law and our commitment to expertise, Mediclinic cannot subscribe to the practice of online diagnosis. Please consult a medical professional for specific medical advice. If you have any major concerns, please see your doctor for an assessment. If you have any cause for concern, your GP will be able to direct you to the appropriate specialists.