What Are Calcium Oxalate Stones and Crystals?

Calcium oxalate stones & crystals are hard, crystalline mineral formations in the kidney or urinary tract

Urine contains many dissolved minerals and salts. Calcium oxalate stones and crystals can form when your urine has high levels of these minerals and salts. Calcium oxalate crystals can start small but can grow larger in size, even filling the inner hollow structures of the kidney.

Crystals in urine symptoms and calcium oxalate stones causes
Crystals in urine symptoms and calcium oxalate stones causes

Crystal in urine symptoms – Some crystals stay in the kidney, and do not cause any problems. Sometimes calcium oxalate crystals can travel down the ureter, the tube between the kidney and the bladder. If the crystal reaches the bladder, it can be passed out of the body in urine. If the crystal becomes lodged in the ureter, it blocks the urine flow from that kidney.

Calcium oxalate stones usually do not cause symptoms until they move through your kidney or passes into your ureters (the tubes connecting the kidneys and the bladder).

If a calcium crystal (or stone) becomes lodged in the ureters, it may block urine flow and cause the kidney to swell. This leads to an ureter spasm, which can be very painful.

If that occurs, the symptoms of calcium oxalate crystals in the urine may be felt.

  • Severe, sharp pain in the side and back, below the ribs
  • Pain that radiates to the lower abdomen and groin
  • Pain that comes in waves and fluctuates in intensity
  • Pain or burning sensation while urinating
  • Pink, red or brown urine
  • Cloudy or foul-smelling urine
  • Persistent need to urinate
  • Urinating more often than usual or urinating in small amounts
  • Nausea and vomiting
    Fever and chills if an infection is present
  • Pain caused by a kidney stone may change — for instance, shifting to a different location or increasing in intensity — as the stone moves through your urinary tract.

Click the link to view common symptoms of kidney stones

In the following pages, we will discuss calcium oxalate stone causes and what are symptoms of high oxalates and crystals in urine symptoms.