Urinary Tract Stones

Overview of Kidney Stones

How are kidney stones formed?

  • Kidney stones are formed within the kidney when some minerals and salts which are filtered through the kidney crystalise to form a stone.
  • 10% of the population will get a kidney stone at some point
  • There are some conditions which can predispose you to having kidney stones. For example: Inflammatory Bowel Disease, Type 2 Diabetes, Obesity, recurrent urine infections, previous treatment with Chemotherapy, and high blood calcium levels
  • Not drinking enough fluid during the day and a diet high in salt can also be a reason why people get kidney stones

Symptoms of Kidney Stones

Symptoms of kidney stones can include severe pain in your side, blood in your urine and a sudden need to pass urine more frequently.

Diagnosing Kidney Stones

What happens next depends on where the stone is between your kidney and the bladder.

The terrible pain people get with kidney stones is a result of the stone moving down the connecting tube (ureter) between the kidney and bladder.

The stone tends to get stuck either just after leaving the kidney, or just before it reaches the bladder.

A CT scan is done to see where the stone is:

  • Stones which are less than 5mm and near the bladder tend to pass out on their own
  • Larger stones in the ureter (>5mm) may need some treatment
  • Stones larger than 5mm in the kidney can be treated before they cause problems by dropping into the ureter.

If you do pass the stone, you should keep it so that it can be analysed.


Treatments for Kidney Stones

  1. Lithotripsy or Shock wave treatment
  • This treatment is done with the patient awake, lying on a bed
  • This treatment is used for stones in the kidney itself, or stones which are very high up or very low down in the ureter
  • Gel is applied to the skin, and an ultrasound machine is then placed onto the gel over the area where the stone is
  • The treatment takes 30 minutes and is only mildly uncomfortable
  • We give between 2 to 3 treatments per stone
  1. Ureteroscopy
  • This is an operation under a general anaesthetic
  • A small telescope inserted through the urethra and up to the stone
  • The stone is broken into pieces by a laser
  • Any large pieces of stone are removed
  • After the stone has been broken up, and to protect the kidney, the patient may temporarily need a stent (plastic internal drainage tube) to be put in place between the bladder and the kidney.  The stent is removed in due course after the procedure via a Flexible Cystoscopy
  1. Percutaneous Nephrolithotomy
  • This is key hole surgery into the kidney done under a general anaesthetic
  • This surgery is recommended for larger stones (>15mm) which are in the kidney itself
  • A tube is placed into the kidney through the skin
  • The stones are broken up within the kidney with an ultrasound probe or a laser, and the stone fragments are taken out
  • A stent (plastic drainage tube) is temporarily placed after the surgery for a few weeks to ensure that the kidney drains properly

I have a kidney stone – how do I prevent getting another one?


It can depend on what type of stone you have made

  • Calcium oxalate is the most common type of stone
  • Uric acid stones are more common in people who are overweight
  • Drinking more than 2.5L of water during the day is recommended
  • Cutting down on dietary salt is also recommended – this is not just salt you add to your food, but salt that is already in food e.g. processed food and drink
  • Losing weight and getting more exercise has been shown to help