Kidney Stones

What are kidney stones?

Kidney stones occur when hard rock-like crystals form from the salts in the urine. They start as microscopic particles and develop into larger stones over time. Dehydration (not drinking enough water) is a major cause of kidney stones as concentrated urine allows the crystals to form more readily.

The most common kidney stones in Australia are made of calcium in combination with oxalate or phosphate. Other stones are made from uric acid – the chemical that causes gout.

Kidney stones are common in Australia. Around one in ten people will develop a kidney stone at some point in their lives. They are about twice as common in men.

What are the symptoms of kidney stones?

Many people with kidney stones have no symptoms at all. A kidney stone can be asymptomatic until it passes from the kidney into the ureter (the tube that carries urine from the kidney to the bladder). Here, the stone can get stuck and cause severe pain.

Common symptoms of kidney stones include:

• Pain – commonly called “renal colic.” This is due to the stone acutely blocking the flow of urine. It can start in the back or flank and move down into the groin on the affected side. Sometimes it can radiate into the scrotum or testicle. People often describe it as the “worst pain ever” and it can cause nausea and vomiting due to its severity.
• Blood in the urine (haematuria).
• Recurrent urinary tract infections.
• Urgent feeling of the need to urinate.

What are the treatments for kidney stones?

The treatment of kidney stones depends on the size and location of the stone. Not all stones require treatment. Many smaller stones will pass on their own and all you will need is pain relief.

Sometimes the stone will be too large to pass or will become stuck in the ureter. In this case, surgery may be needed. A stent (a hollow plastic tube) can be placed between the kidney and bladder to allow the drainage of urine. This is a temporary measure to relieve pain and allow the kidney to drain. 

There are many different treatments available depending on the size and location of your stone. These include:

• Extracorporeal shockwave lithotripsy (ESWL) – under general anaesthetic, shockwaves are used to break the stone into small fragments which your body can then pass
• Ureteroscopy – a small camera (ureteroscope) is passed to the ureter or kidney through the urethra. A stone can then be removed using a basket or broken into tiny fragments using a laser
• Percutaneous nephrolithotomy (PCNL) – used for larger stones (>2cm) in the kidney. A telescope is passed through the skin in the flank directly into the kidney. The stone is then broken and removed.