Kidney Stones
There are four main types of kidney stones:
Calcium Stones:This is the most common type of kidney stone, which occurs in about 70 – 80% of cases. Calcium stones are usually composed of calcium oxalate and less commonly, of calcium phosphate. Calcium oxalate stones are relatively hard and difficult to dissolve with medical management. Calcium phosphate stones are found in alkaline urine.
Struvite Stones: Struvite (Magnesium ammonium phosphate) stones are less common (about 10 – 15%) and result from infections in the kidney. A struvite stone is more common in women and grows only in alkaline urine.
Uric Acid Stones:Uric acid stones are not very common (about 5 – 10%) and are more likely to form when there is too much uric acid in the urine and urine is persistently acidic. Uric acid stones can form in people with gout, who eat a high animal protein diet, are dehydrated or have undergone chemotherapy. Uric acid stones are radiolucent, so are not detected by an X-ray of the abdomen.
Cystine Stones:Cystine stones are rare and occur in an inherited condition called cystinuria. Cystinuria is characterized by high levels of cystine in the urine.
Several factors that increase the risk of developing kidney stones are:
- Reduced fluid – especially decreased water intake and dehydration.
- Family history of kidney stones.
- Diet: consuming a diet high in animal protein, sodium and oxalate, but low in fiber and potassium rich citrus fruits.
- 75 % of kidney stones and 95% of bladder stones occur in men. Men between the age of 20 to 70 years and those who are obese are most vulnerable.
- A person who is bed-ridden or immobile for a long period.
- A person living in a hot humid atmosphere.
- Recurrent urinary tract infections and blockage to the flow of urine.
- Metabolic diseases: hyperparathyroidism, cystinuria, gout etc.
- Use of certain medications such as diuretics and antacids.
The symptoms of urinary stone may vary with size, shape, and location of the urinary stone. Common symptoms of urinary stone are:
- Abdominal pain.
- No symptoms. Accidental detection of urinary stone on routine health checkups or during the workup for unrelated conditions. Stones that do not cause any symptoms and are detected accidentally on radiological examinations are known as “silent stones.”
- Frequency of urination and persistent urge to urinate is found in patients with a urinary bladder stone.
- Nausea or vomiting.
- Passage of blood in urine (hematuria).
- Pain and/or burning while passing urine.
- If the bladder stone gets stuck at the entrance to the urethra, the flow of urine suddenly stops during urination.
- Passage of stones in urine.
- In a few cases urinary stones can cause complications such as recurrent urinary tract infection and obstruction of the urinary tract, causing temporary or permanent damage to the kidney.
