Kidney stones are a common urological problem that may cause discomfort and pain during urination.
What Causes Kidney Stones?
Kidney or urinary stones are formed when minerals in the urine separate and crystallise due to a chemical imbalance. Normally, the urine contains chemicals that prevent these crystals from forming. Because they often occur in the kidneys and urinary system, these crystals are called kidney or urinary stones.
Risk Factors for Kidney Stones
• Family or personal history
• Dehydration
• Diets high in animal protein, salt and sugar
• Urinary infections or urinary tract obstruction
• Obesity
• Metabolic diseases such as hyperthyroidism, gout, renal tubular acidosis, and cystic renal disease
• Digestive diseases and gastric surgery
• Certain medications and supplements
The Minerals Within Us
Kidney stones are made of various combinations of chemicals and are categorised as calcium-containing (a common form) and non-calcium-containing stones. Depending on their mineral composition, the appearance and hardness of urinary stones vary.
Kidney Stone Symptoms
Very small crystals may travel through the urinary tract and pass out of the body in the urine without being noticed, so many people are unaware that they have a kidney stone. However, when kidney stones move around within the kidney or pass into the ureter (the tube connecting the kidney and bladder) they can cause symptoms such as:
• Pain in the lower abdomen and groin; the pain may come in waves and fluctuate in intensity
• Nausea and vomiting
• A change in the frequency and volume of urinating
• Discoloured, cloudy, and foul-smelling urine
• Fever
• Blood in the urine
• Difficulty in passing urine
Seek emergency treatment if the pain is severe and if there are fever or chills, vomiting, or blood in the urine.
Detecting Kidney Stones
A computerised tomography (CT) scan of the urinary system is the gold standard for diagnosis. To determine baseline kidney function and any infection, blood and urine tests may also be needed.
Treatment for Kidney Stones
For smaller stones, the patient may be given medication to help flush out the stone in the urine. The patient will need to drink about two to three litres of water a day to help flush out the stone.
For larger stones, a procedure called extracorporeal shock wave lithotripsy may be used. Sound is used to create “shock waves” that break stones into tiny pieces that can be passed out in the urine. The procedure is done under sedation or light anaesthesia.
If the stone is too large to pass naturally, or trapped in an awkward place, or causing significant pain, it may need to be treated surgically. This involves reaching the stone via the urethra with a long scope equipped with a video camera and a device that fragments the stone before it is removed. For larger stones, a small incision will be made at the back (or loin) so that a larger scope can be inserted into the kidney.
After surgery, the stones are analysed for their chemical composition so that medication, lifestyle or diet changes can be recommended to prevent a recurrence.
Preventing Kidney Stones
Prevention methods include keeping hydrated (with about 2.5 litres of water a day, or enough to keep the urine light and clear) and following a diet low in salt, animal protein and oxalate-rich foods (such as nuts, tea, chocolate and soy products).
It is also important to maintain a diet high in calcium, but to use calcium supplements with caution. Kidney stones tend to recur in about 50 percent of cases, so prevention is the best course of action.
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