Ask the Expert

What are Kidney Stones?

Spread the love


  • Kidney stones are also known as renal calculi. They are tiny stones that are formed due to aggregation of crystal.
  • These renal stones or calculi can occur anywhere in the urinary tract which includes the kidneys, the renal pelvis, the ureter, the bladder and the urethra.
  • The renal stones are made up of many different elements and hence are named according to the predominant substance that constitutes the calculus.
  • The common type of calculi are made up of Calcium, Uric acid, cystine and struvite .
  • The calcium stones are most common. The stones are usually calcium oxalate and they can be prevented if oxalate containing foods are restricted in the diet. Some of the oxalate containing foods are spinach, peanuts, chocolate and beets. Sometime the stones may also be calcium phosphate and calcium maleate stones.
  • Reducing the amount of dietary calcium does not cause a decrease in the formation of these stones
  • Uric acid stones are also common and they occur in cases of Gout. The other conditions  that can cause an increase in the uric acid level are some cancers and chemotherapy
  • Uric acid is deposited when the pH of urine is more acidic.
  • Foods that cause acidification of urine will cause more deposition of Uric acid in the urine. Some such foods are meats and fishes.
  • Struvite stone occur in women who have repeated urinary tract infections. These calculi can be treated by treating the infection
  • Cystine stones are found in patients who have cystineurea or they pass high amount of cysteine in the urine. This is a genetic condition.
  • Anyone can have renal calculi but females are more prone than males
  • People who have history of renal stones in other family members are more likely to have stones.
  • People who are obese, have diet with high protein, salt and sugar content , and are  on drugs such as diuretics , ant epileptics and antacids are more likely to have  renal stones
  • Dehydration will also precipitate crystals in the urinary tract and  this will then start the formation of a calculus with more and more crystals depositing
  • Hyperparathyroidism  also causes formation of stone in the kidney and sometimes this condition is diagnosed during investigation of a renal stone
  • Gastric bypass surgery and Inflammatory bowel disease can also increase the risk of having renal calculi
  • The symptoms of renal calculi are classically described as colic. The patient suffers from severe abdominal pain with nausea and vomiting
  • The pain is associated with blood in the urine  classically called haematuria
  • The patient may also have repeated urinary tract infections along with fever and chills and rigors
  • It is important to diagnose and treat renal stones because if not treated they may cause  severe complications
  • There may be an obstruction to the urinary flow causing back pressure and damage to the kidney
  • The urinary tract infection may travel backwards to the kidneys
  • It is therefore extremely important that the patient be investigated
  • The tests include blood tests for the estimation of calcium, phosphorous, uric acid and electrolytes.
  • The functioning of the kidney can be done by assessed by estimating the levels of Urea and Creatinine
  • The levels of the Parathormone also needs to be assessed to rule out hyper parathyroidism
  • The urine is examined to rule out infection and also to look for casts and crystals
  • The stone that are passed are also examined and analysed to assess the type of stone so that necessary dietary precautions can be taken
  • In addition to the blood tests some imaging test are also done – These include abdominal x-ray, intravenous pyelogram also known as IVP, Ultrasound of the Kidney and pelvic area, and sometines CT and Mri of the abdomen.

You may also like...

Leave a Reply

Your email address will not be published. Required fields are marked *