Kidney Stones

Most people have two kidneys. They clean the blood by filtering out water and waste products, making urine.

Kidney stones are fairly common - about 12 in every 100 men and 4 in every 100 women in the UK experience them at some point.

Kidney stones are small, solid masses that form when salts or minerals normally found in urine form solid crystals (crystallise) inside the kidney. In most cases, the crystals are too tiny to be noticed, and pass harmlessly out of your body. However, they can build up inside your kidney and form much larger stones.

Kidney stones are usually painless when in the kidney but can cause severe pain as they travel from the kidneys to the bladder. An attack of this pain is called renal or ureteric colic. If a stone gets stuck in the ureter, this can cause an infection which can lead to permanent kidney damage.


Many kidney stones don’t move and are too small to cause any symptoms. However, if a kidney stone causes a blockage, or moves into the ureter, it may cause:

  • Severe pain or aching in the back on one or both sides 
  • Sudden spasms of excruciating pain, usually starting in the back below the ribs and radiating around the abdomen, sometimes to the groin and genitalia 
  • Bloody, cloudy or smelly urine 
  • Feeling or being sick 
  • A frequent urge to urinate, or a burning sensation during urination 
  • Fever and chills

These can also be symptoms of a urinary tract infection, or cystitis, which is much more common than kidney stones in young women. If you have one or more of these symptoms you should seek medical advice.

Contributory factors

Dehydration: not consuming enough water leads to more concentrated urine – the more concentrated the urine, the greater the chance of forming kidney stones.

Gradually increasing your water consumption can help to dilute the urine and reduce the prevalence of stone formation.

Poor diet: a diet low in fibre and high in protein creates a lot of work for the kidneys and can contribute to stone formation. Foods containing substances called oxalates and purines can also increase the chance of stone formation.

If you suffer from kidney stones or have a family history of the condition, Smart Nutrition’s nutritional therapists can advise you on the best diet for kidney health. Please use the button at the bottom of this page to find out more.

Mineral imbalance: an excess of the mineral calcium or improper distribution of calcium in the body can also contribute to kidney stones.

Blood sugar imbalance: starchy/sweet foods and alcohol are broken down in the body into a sugar called glucose. This is carried around in the blood stream and taken to cells which use it for energy.

The level of glucose in the blood is carefully controlled by a hormone called insulin. After we eat, the amount of glucose in the blood rises. Insulin is released to bring blood glucose levels back down to normal levels. However, if blood sugar rises too rapidly, the body can end up releasing too much insulin. This causes the blood sugar to swing to low again, making us feel tired, grumpy and hungry again. This is sometimes referred to as the blood sugar rollercoaster.

Excess insulin is that is causes extra calcium to be lost in the urine. This extra calcium has to go out via the kidneys, increasing the risk of stone formation.

If you suffer from the symptoms associated with blood sugar imbalance, an Insulin Resistance Test can identify your body’s efficiency at controlling this. A nutrition consultation also gives invaluable advice on how to even out your blood sugar levels. 

Urinary tract infections (UTIs): one type of kidney stone can form during a urinary tract infection. If you suffer from recurrent UTIs such as cystitis, you’re at greater risk of forming this kind of stone.

There are many natural ways in which you can support a healthy urinary tract and decrease the risk of infections. Smart Nutrition can provide support – please use the button at the bottom of this page to find out more.

Smoking: cigarettes contain the toxic metal cadmium which has been linked to kidney stone formation.

Avoiding smoking is a key consideration for kidney stone sufferers, but not always an easy step to take. Working with a nutritional therapist can be of great support during the process of quitting smoking. Diet and supplements can help to reduce cravings and support the body in its move to a healthier state.

Useful Links

Please do not return samples to the laboratories that may arrive after Wednesday 27th March and up to and including Monday 2nd April.

The laboratories are closed from the 28th March – 2nd April for the Easter Holiday.