What are kidney stones?

A kidney stone is a hard lump that forms in the kidney. It is made from some of the minerals that are in your urine. If there are too many minerals in your urine they can form crystals. Over time, these crystals join together to make stones.

Some people get stones in their bladder. This can happen if your bladder does not empty fully, or if stones move down from the kidney.

What are the symptoms?

If the kidney stones are small, you may not have any symptoms. Most people will pass them out when they have a pee if they are small. You may not know that you have them. Sometimes it can be painful when they are passed out.

If the kidney stones are bigger, they can get stuck in the tube that takes urine from your kidney to your bladder. If this happens it may block the flow of urine. This may cause

• Pain
• Cloudy, smelly urine. This can be a sign of infection
• Temperature
• Feeling sick and vomiting
• Blood in your urine

What causes kidney stones?

The risk of getting kidney stones can depend on a few things.

• Men are more likely to get kidney stones than women.
• Not drinking enough. Being overweight.
• Eating food that has a lot of oxalate can cause kidney stones.
• Too much salt.

Treatments for kidney stones

There are a few different types of treatment for kidney stones.

• Helping the pain while you pass the stone. You can do this by drinking a lot of water or squash. Your doctor can give you strong pain killers to help the pain.
• Breaking up the stones into tiny pieces using shockwaves or lasers. They will then pass out when you pee.
• Surgery to take the stones out.

Breaking up kidney stones with shockwaves

This treatment is called extracorporeal shockwave lithotripsy (ESWL). Lithotripsy uses shockwaves to break a kidney stone into tiny pieces. They can then pass out of your body naturally when you pee. An X-ray or ultrasound scan helps your doctor find the stones before the treatment starts.

What happens on the day?

A specialist doctor called a urologist usually does this procedure. It can also be done by a trained lithotripsy technician.

• The medical team will make sure you don’t have a urine infection before the procedure. You will need to give a sample of your pee for them to check.
• Before the procedure starts, you may have an X-ray. This is to check the position of the stone. It may have moved.
• Don’t have anything to eat in the 6 hours before the treatment.
• Only drink clear fluids in the 6 to 2 hours before treatment.
• Do not eat or drink 2 hours before treatment.
• The medical team will give you pain killers before the treatment starts.

You will be awake during the treatment. Sometimes you get medicine to make you drowsy.

You will lie on a treatment bed. We use an X-ray or ultrasound so we can see exactly where the stones are. We put gel or water on your skin. The shockwaves will travel through this. A large machine sends shockwaves to the stone.

Each shockwave feels like a flick with an elastic band. You might feel a deeper ache in your kidney. Ask for extra pain relief or sedation if you need it. The team may pause during the treatment to check the stone’s position.

The treatment usually takes 30–60 minutes.

Most people can go home the same day. You will need to get someone else to drive you home.

Breaking up kidney stones with laser energy

This treatment is called a ureteroscopy. The doctor will use a long thin camera. This is known as a ureteroscope. The stones can be in your bladder or inside the kidney. They break the stones up with a laser light passed through a thin fibre. If the stones are too big, you may also need keyhole surgery.

What happens on the day?

A specialist doctor called a urologist usually does this procedure. Most people have a general anaesthetic. This is where the operation is done whilst you are asleep.

The surgeon will look inside your bladder using a long narrow camera. They put a fine guide wire into your kidney to reach the stone. Then they use the guide wire to put in the ureteroscope.

The surgeon breaks up the stone using a laser light. The surgeon may put in a ureteric stent. This is a soft tube that sits between your kidney and bladder. It helps urine to drain from your kidney. It will be taken out after a few weeks.

Some people may need another ureteroscope operation later. This is to clear any leftover stones. If this happens, your stent will stay in until the next operation.

Most people go home the same day.

Surgery to take bigger stones out

There are different types of surgery used to take out kidney stones. Which one you have will depend on the size and shape of your kidney stones.

• Percutaneous Nephrolithotomy
• Open surgery

Percutaneous Nephrolithotomy

Doctors call this PCNL for short. It is a type of keyhole surgery. Doctors use it to remove stones from your kidney that are too big for other methods.

What happens on the day?

Most people have a general anaesthetic for this surgery. They will be asleep the whole time. Don’t have anything to eat in the 6 hours before the treatment.

The surgeon puts a narrow tube into your bladder. This tube drains the urine out and helps guide the procedure.

Then they make a small hole in your back to reach the kidney. The cut is about 1cm.

They use an ultrasound or an x-ray to carefully pass a fine needle into your kidney. When the needle is in the right place, a wire is passed through it. The opening is then gently stretched to make a path into the kidney. They pass a tiny narrow camera into the kidney to see the stone. Doctors call this a scope.

The stone is broken into small pieces using a laser, drill, or sound waves. Bigger pieces are taken out using small tools or suction.

The surgeon may also put a soft tube between your kidney and bladder. The medical team calls this a stent. This helps drain your urine whilst the kidney heals.

The surgery takes between 1 and 3 hours.

Most people stay in hospital for about 3 days. Some people may go home the same day.

Open surgery

This is an operation where the surgeon makes a long cut to reach the stones in your kidney. It is not often done these days. It is only used if

• The kidney stone is very large
• Other treatments do not work
• There are problems with the shape of the kidney
• It is not safe to use keyhole surgery

What happens on the day?

Most people have a general anaesthetic for this operation. This is where it is done whilst you are asleep. Don’t have anything to eat in the 6 hours before the treatment.

The surgeon makes a large cut in your tummy or your side to reach the kidney. The surgeon cuts open the kidney to take out the stone.

When the stone has been taken out, the surgeon closes the kidney using stitches. These will melt away after about 2 weeks. Then they close the wound with stitches or staples. The surgeon may also put a soft tube between your kidney and bladder. The medical team calls this a stent. This helps drain your urine whilst the kidney heals.

The operation usually takes between 2 and 4 hours. Most people stay in hospital for about a week. It will take longer to recover than keyhole surgery. It may take up to 2 months to fully recover.

Most people have more pain after open surgery than with keyhole surgery. The scar is also bigger. You will not be able to lift anything heavy or do strenuous exercise until you have recovered.

Costs for kidney stone treatments

Most private health insurance policies cover tests and treatment for kidney stones.

If you self-funding then there a few costs to consider. Tests to find out if you have kidney stones can cost about £1,000. This would include a consultation with the doctor, scans and urine tests.

The cost of removing kidney stones can range between about £4,000 and £5,000. It can cost more if the stones are big or complicated. A PCNL can cost between £6,000 and £8,000.

References

Khan SR, Pearle MS, Robertson WG, Gambaro G, Canales BK, Doizi S, Traxer O, Tiselius HG. Kidney stones. Nat Rev Dis Primers. 2016 Feb 25;2:16008. doi: 10.1038/nrdp.2016.8. PMID: 27188687; PMCID: PMC5685519.

NICE guidance 118 Renal and ureteric stones. 2019

Ferraro PM, Taylor EN, Curhan GC. Factors associated with sex differences in the risk of kidney stones. Nephrol Dial Transplant. 2023 Jan 23;38(1):177-183.

BAUS – I think I have kidney stones: Kidney stones (PDF)