Kidney stones

Understanding what kidney stones are, how they are treated, and how you take measures to prevent them is all part of caring for your kidneys.

Understanding kidney stones and how to prevent them

The development of kidney stones is one of the most common disorders of the urinary tract, with four to eight per cent of Australians experiencing them at some time. Those odds are increased if you have a family history of kidney stones, or if you’re elderly.

The good news is, kidney stones can be treated. You can also take preventative measures by staying hydrated with water.

All about kidney stones

It’s the kidney’s job to filter blood and remove extra waste and water, which gets passed as urine. Urine contains many waste chemicals, which can sometimes form crystals that clump together – and these clumps are kidney stones. The stones are hard, rock-like crystals of varying sizes and shapes; anywhere from as small as a grain of sand to a golf ball.

There are four main types of kidney stones:

Calcium stones combined with oxalate or phosphate are the most common.
Struvite stones are often horn-shaped and quite large, mostly caused by urine infections.
Uric acid stones are often softer than other forms of kidney stones.
Cystine stones are rare and hereditary. They look more like crystals than stones.

Dehydration is a common cause of kidney stones. Drinking inadequate amounts of water for prolonged periods of time greatly increases your risk. If you live in hot and dry climates, or sweat a lot, you are also at increased risk.

Another common cause of kidney stones is an imbalance of substances in your urine, i.e. high levels of calcium, oxalate, cystine acid or uric acid. This can happen if you:

have an underlying medical condition (such as a urinary tract infection, diseases of the digestive tract, inflammatory bowel disease, hyperparathyroidism, sarcoidosis, and some cancers)
use certain medications to treat conditions such as kidney disease, cancer or HIV
eat foods high in salt (this increases acid levels in your body).

While it’s not common, kidney stones can potentially lead to acute kidney injury or chronic kidney disease. This can happen two ways:

Obstruction – if a stone blocks the flow of urine out of your kidney, and this is left untreated, your kidney could become damaged. However, this is unusual as kidney stones cause symptoms, so most people have them removed.
Recurrent infections and inflammation – After you have had a kidney stone, you are more likely to experience another one in the future – your doctor can work with you on ways to reduce this risk. Some people continue to get kidney stones their whole lives. If this happens, you are at risk of chronic urinary tract infections and inflammation. This can lead to scarring of the kidneys, and eventually, chronic kidney disease.

When you have kidney stones, pain is usually the first sign. This often occurs when the stone moves from where it was formed in the urinary tract. You’ll typically experience a gripping pain in your back, just below your ribs. It can spread around to the front of your body, and sometimes towards your groin.

Some other symptoms of kidney stones include:

blood in your urine
nausea and vomiting
shivers, sweating and fever, with cloudy or bad smelling urine if there’s also an infection
small uric acid stones, which look like gravel, in your urine
an urgent feeling of needing to urinate.

After experiencing the pain associated with kidney stones, your doctor may want you to undergo some specific tests to confirm the diagnosis. These include:

an ultrasound
CT scans
X-rays, including an intravenous pyelogram (IVP), where dye is injected into the bloodstream before the X-ray is taken.

After confirming kidney stones, your doctor may also order urine and blood tests to find out their cause. This will help them to work out a treatment plan.

Most kidney stones will pass by themselves within three to six weeks. In this case, the only treatment required is pain relief. Sometimes, if the pain is severe, you may be admitted to hospital and put on stronger painkillers.

If a stone doesn’t pass on its own, and begins to block the flow of urine, or causes bleeding or an infection, you may need one of the following treatments:

Breaking down the kidney stones into smaller pieces using ultrasound waves. This is usually used for stones less than two centimetres in size.
Removing the kidney stone through a small incision in your back.
Removing or breaking up the kidney stone by inserting an instrument through the urethra into the bladder, then to where the stone is located.

It’s important to understand the risks and symptoms of kidney stones to properly care for your kidneys. To find out what you can do, read our kidney stone fact sheet.

For more information, check out Kidney Health Australia’s resources library.