Kidney stones Q&A

Mr Ben Grey is a consultant urological surgeon practising all components of general urology at The Alexandra Hospital. He has a subspecialty interest in stone management, and here he answers your commonly asked questions about kidney stone disease, including the causes, symptoms and treatments.

What is kidney stone disease?

Urinary tract stone disease (urolithiasis) is a condition whereby stones (calculi) form within the urine. Men are usually affected more than women, but the prevalence in both appears to be on the increase, as are the numbers of children and young adults affected by the condition.

What causes kidney stones? 

The kidneys work to cleanse the body of waste products, maintain hydration and ensure the body's balance of salts and minerals is correct. If there becomes an excess of waste material, salt or minerals, or if there is not enough water within the urine, crystals can form and subsequently clump together to form stones.

What are the symptoms of stone disease? 

Stones can result in blood in the urine (haematuria), and may also cause urinary tract infections and pain. If the stones are small or are only present in the kidneys, there may not be any symptoms at all. Stones may cause problems with urine draining from the kidney, for example the stones may move into the ureter, a narrow tube which carries urine to the bladder. If this happens patients can experience severe pain, which may be sudden in onset and be incapacitating enough to require hospitalisation.

How are kidney stones diagnosed? 

The specialist can usually diagnose the condition through the patient's description of their symptoms, but confirmation is usually made with a CT scan. CT scans to detect stone disease only require relatively low doses of radiation, plus they can rapidly help the specialist to advise whether intervention is required and the most suitable treatment option for a given stone's size and position.

The Alexandra Hospital offers rapid access to both diagnostic imaging and a specialist opinion, which often helps to alleviate anxiety as well as the length of the patient's treatment pathway.

How are kidney stones treated? 

There are a number of treatment options available. A good surgeon will consider not only the stone that requires urgent treatment, but also whether there are any other stones within the urinary tract that could be treated simultaneously to avoid future symptoms. Of course, the overall health of the patient and their suitability for the treatment options is an extremely important consideration. Equally, private patients benefit from a shorter treatment pathway and an earlier return to work.

Treatment options include:

Conservative treatment

Depending on the size and position of stones, the specialist may suggest just monitoring the patient. This may work for those patients who have small stones in the ureter that have a high likelihood of passing through, or stones in the kidney that cause no symptoms. Equally, conservative treatment may be preferred for those patients with associated high risk medical conditions.

Medical treatment

Certain types of stones (e.g. Uric Acid) can be dissolved after accurate diagnosis of the stone type. It can be difficult to elicit the type of stone unless there is an associated medical condition or piece of stone available for formal analysis.

Extracorporeal Shock Wave Lithotripsy (ESWL)

This treatment is non-invasive and doesn't require an anaesthetic. X-rays or ultrasound are used to find the stone and then shock waves are focused from outside the body on to the stone, cracking it into smaller pieces which then pass out of the body in the patient's urine.

Ureteroscopy

This minimally-invasive treatment is performed under general anaesthetic and involves a small camera (ureteroscope) being passed through the bladder to the ureter and/or kidney, depending on where the stone is situated. Commonly, a laser is then used to fragment the stone into small pieces which then either pass out the body in the urine, or can be helped out with small basket retrieval devices.

PerCutaneous NephroLithotomy (PCNL)

This is another minimally invasive technique performed under general anaesthetic, accessing the kidney and/ or the ureter via a small skin incision in the back. A larger camera (nephroscope) and ultrasonic/hydraulic fragmentation device or a laser is used to treat larger kidney stones and stones in the ureter which can't be accessed by a ureteroscope.

A specialist in stone treatment should be able to discuss the benefits and risks associated with each of the treatments, so a bespoke treatment plan can be tailored to the individual patient's condition and needs.

How can you prevent kidney stones from forming? 

Stones have always been more common in hot climates. The fact that stones are now becoming more common in Western society suggests a link to lifestyle. The reported scientific literature supports associations with diet and obesity as well as, most importantly, not drinking enough water.

A good specialist will not only treat a patient's stones but should also investigate why they formed in the first place, so they can tailor advice about prevention to the individual. Understandably, once a patient has had experience of stone disease, they want to try and avoid recurrence however, 50% of patients are thought to recur over the subsequent 10 years, reinforcing the importance of prevention advice.