Kidney Stones

Kidney stones are painful urinary disorders. Kidney stones start as salt/chemical crystals that precipitate out from urine. Under normal circumstances, urine contains substances that prevent crystallisation but for patients with this condition, these inhibitory substances are ineffective. Tiny crystals will pass out along with the urinary flow without causing problems. Kidney stones may contain various forms of salts – the most common is calcium in combination with either phosphate or oxalate. These salts are an essential part of our daily dietary intake and requirement. Other types of stones are the struvite stone (caused by infection), uric acid stone and cystine stone.


Kidney stone disease is a little more common in males (men) and usually in those between age 20-40. Possible causes of kidney stones formation are:

  • Drinking too little water
  • Too much or too little exercise
  • Obesity
  • Weight loss surgery
  • Consuming too much salt
  • Infections
  • Consuming too much fructose
  • Family history of kidney stones
  • Certain medications and/or supplements
  • Metabolic conditions e.g. gout (excess uric acid), hyperparathyroidism, cystinuria (inherited disease), and hyperoxaluria (inherited disease) are also common causes of stone formation

There is certainly a strong familial predisposition to this condition. There are those that simply absorb excessive calcium and excrete the extra calcium through the urine. High levels of urinary calcium causes crystallisation and subsequent stone formation.

Excessive intake of vitamin D and some medications (diuretics) may also give rise to excessive calcium in the urine. Metabolic conditions e.g. gout (excess uric acid), hyperparathyroidism, cystinuria (inherited disease), and hyperoxaluria (inherited disease) are also common causes of stone formation. 

Signs and Symptoms

  • Painful and/or difficult urination
  • Unable to pass urine if the stone is large enough to obstruct the outlet completely
  • Blood in the urine (abrasion along the urinary tract as the stone travels)
  • Extreme pain at the site where the stone is causing the irritation (back and flanks of the abdomen, lower front of the abdomen, groin area)



  • With plenty of water, most stones can pass through if small
  • Pain-killers (as prescribed by the doctor)
  • Some medications may help ‘break down’ larger stone
  • Shockwave therapy (F-SWL) to break the stone
  • Surgical intervention – cystoscopy or open surgery





Prevention is very important especially in those with a high likelihood of developing this condition. Recurrence rate for stone formation is very high.


  • Medical therapy is available for those with known conditions that render them predisposed to stone formation
  • Eat more fruits and vegetables
    Eat more fruits and vegetables, which make the urine less acidic. When the urine is less acidic, stones may be less likely to form.
  • Those prone to get calcium oxalate stones may be advised to avoid the consumption of foods high in oxalates (cola, coffee, chocolate, nuts, spinach, strawberries, wheat bran, tea)
  • Reduce excess salt from diet
    Too much sodium (salt) consumption increases the urinary calcium excretion and potassium along with citrate, resulting in a change of urinary pH value that will eventually increase the risk of stone formation.
  • Drinking a lot of water is best (enough to produce about 2 liters of urine a day)
    When there is too little fluid and too much waste in urine, crystals begin to form, the first step in forming a stone. Drinking enough water helps to dilute the urine and prevents chemicals in the urine from forming crystals. It also helps to excrete chemicals from body and prevent stone formation. You are recommended to drink 2-3L of water a day. You may need to drink more if you have concentrated urine.

Remember that left untreated, a kidney stone will cause damage to the kidneys and may even lead to end stage kidney failure. One with a past history of kidney stones should have regular screenings done as recurrence rate is high.