Kidney stones are a common problem in the UK; around 1 in 10 of people are likely to form a kidney stone at some point in their lives. They are composed of the chemicals that are excreted normally in the urine, and most stones contain calcium. Although they may go undetected, kidney stone scan give rise to a number of symptoms including:
- Severe abdominal pain which tends to be felt around the flank and may radiate down to the groin on the affected side. This is called “renal colic” and often requires emergency admission to hospital for strong pain relief and treatment. This usually happens when a kidney stone moves out of the kidney into the tube between the kidney and bladder (this is called the ureter).
- Blood in the urine
- Recurrent or persistent urinary tract infections
If left untreated, kidney stones may grow larger and eventually cause damage to the kidney, although many stones remain small and may not require treatment.
What causes kidney stones?
There are a few, relatively uncommon underlying medical conditions which may result in stone formation. However, the vast majority of people who form kidney stones do not have an underlying health condition. It is thought that these patients have a genetic susceptibility to kidney stones combined with a lifestyle and dietary habits which encourage kidney stone formation. As part of your consultation, we can discuss investigations into why you are forming stones, particularly if you have had several episodes of kidney stones. We will also be available to advise you on how to reduce your risk of stone formation in the future.
How are kidney stones diagnosed?
We use various forms of diagnostic imaging to diagnose kidney stones. These include abdominal X-rays, ultrasound scans and CT scans, with the latter being the most accurate way of imaging kidney stones.
When do kidney stones need treating?
This can be a complex topic, and there are many kidney stones which do not require treatment. Even small stones which have moved from the kidney into the ureter have a high chance of being passed spontaneously without treatment. Therefore, the indications for treating stones include:
- Stones which have become lodged in the ureter and are unlikely to pass spontaneously
- Stones within the kidney which are giving rise to bleeding, pain or infections, or are thought to be affecting the function of the kidney
Your urologist will carefully discuss all these conditions with you. Many stones do not require immediate treatment, but do need to be carefully followed up.
How are kidney stones treated?
If stones do need treating surgically, there are 3 main approaches.
This can be used to treat smaller stones in the kidney and in certain parts of the ureter. This treatment is non-invasive, does not require anaesthesia, and is carried out on an outpatient basis.
Ureteroscopy and laser
An operation under anaesthesia whereby a small telescope is passed up to the stone internally, and a laser is used to fragment the stone.
An operation under anaesthesia whereby a small keyhole incision is made into the kidney, through which a telescope can be passed in order to break up and remove stones. This is usually reserved for patients with larger kidney stones, which are harder to treat by shockwave lithotripsy or ureteroscopy.
How can I prevent kidney stones?
Patients with a tendency to form stones can reduce the risk of recurrent stones by taking the following simple dietary measures.
- Increase fluid intake – this is the most important preventative measure. You need to drink enough fluid so that during the day, the colour of the urine is very pale yellow or clear. Typically, this will equate to a fluid intake of over 2 litres/day, although this may vary according to the atmospheric temperature and your level of physical activity.
- Reduce dietary salt intake: reducing your salt intake can benefit your health in many ways, and has been shown to reduce the risk of stone formation in some patients.
Reducing dietary fat and animal protein (ie any form of meat including poultry and fish) intake.