What are kidney stones?

Kidney stones are crystalline stones (also called calculi) that form in your kidneys or ureters. Your ureters are the tubes connecting your kidneys to your bladder.

Kidney stones are a common problem that can cause severe pain. They tend to be more common in males than females.

There are many types of kidney stones. They can be made of:

• calcium oxalate
• calcium phosphate
• uric acid

Less common types of kidney stones are struvite stones and cystine stones.

Other names for kidney stones include:

• renal calculi
• nephrolithiasis
• urolithiasis

What are the symptoms of kidney stones?

Stones in your kidneys or ureters can cause pain. This pain is often severe and can come and go — it is called renal colic.

Typical symptoms of kidney stones include severe pain in:

• one side of your back
• your side
• your lower tummy
• your groin — which may also be felt in your tummy or back

If you have kidney stones, you may also:

• have nausea (feeling sick)
• be vomiting (being sick)
• have blood in your urine
• feel like you need to pass urine often or urgently

Some people have no symptoms with a kidney stone.

What causes kidney stones?

Your kidneys are part of your urinary system. They remove waste products from your blood to form urine (wee).

Urine contains many waste chemicals which can clump together into hard crystals. These hard crystals are kidney stones.

You're more likely to get kidney stones if:

• you are often dehydrated
• you have a diet that's high in salt and meat
• you drink a lot of carbonated soft drinks (soft drinks)
• you've had a kidney stone before
• kidney stones run in your family
• you take certain medicines
• you are overweight or obese

Some kidney stones are caused by a urinary tract infection or a rare inherited condition.

When should I see my doctor?

See your doctor as soon as possible if you have symptoms of renal colic. If the pain is very severe, go to your nearest emergency department.

Also see your doctor straight away or go to your nearest hospital emergency department if you have renal colic and signs of infection, such as a fever.

How are kidney stones diagnosed?

Your doctor will ask about your symptoms and do a physical examination. They may do a urine dipstick test in the clinic, as well as order tests, such as:

• blood tests
• urine tests
• imaging tests such as a CT scan, ultrasound scan or x-ray

Your doctor may refer you to a urologist for treatment.

How are kidney stones treated?

Your treatment will depend on:

• the type of stone you have
• the size of the kidney stone or stones
• where the stone is
• if your urinary system is blocked
• if there is an infection

Most kidney stones will come out by themselves in your urine. This can take up to 6 weeks. Treatments to help with your symptoms and help the stone pass include:

• taking pain-relief medicines
• drinking plenty of clear fluids, such as water
• medicine to help pass the stone

Your doctor may recommend straining your urine to catch the stone when it passes.

Surgery or other procedures

You might need to see a urologist for treatment if:

• you have a large stone
• your stone does not pass on its own
• your pain is not responding to pain-relief medicines

There are several treatment options are available, such as:

• laser treatment to break up the stone and remove the fragments — this is done using a cystoscope
• treatments to break up the stone so that the fragments are small enough to pass in your urine
• a procedure or operation to remove the stone

Procedures to remove kidney stones can sometimes lead to complications. These can include bleeding and infection. You can discuss with your doctor the side effects of different treatments and which treatment would be best for you.

What are the complications of kidney stones?

Kidney stones can sometimes obstruct (block) the flow of urine. Stones in your ureter can cause a complete or partial blockage. If your kidney stones block your urinary system you will need to have treatment in hospital.

There can be a urinary tract infection at the same time as a kidney stone. If this happens, you will need urgent treatment with antibiotics and treatment for the kidney stone.

Sometimes kidney stones can damage the ureter, causing scarring. This can cause narrowing that may need to be treated.

Kidney stones can also happen again, especially if you:

• are young
• are overweight
• have family members who have had kidney stones

Can kidney stones be prevented?

There are things you can do to reduce the chance of getting kidney stones. These include:

• drinking plenty of fluids every day — so that your urine is clear
• eating a healthy, balanced diet with plenty of fibre
• reducing the amount of fat and animal protein (meat) you eat
• reducing the amount of salt you eat
• maintaining a healthy body weight

If you've had kidney stones before, your doctor may recommend specific treatments to prevent more stones. Their advice will depend on the type of kidney stone you had.

Resources and Support

For more information on kidney stones and other kidney problems, visit the Kidney Health Australia website. There is information on kidney disease in languages other than English.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.