Types of Kidney and Ureteral Stones

There are four main types of kidney and ureteral stones - calcium, uric acid, struvite and cystine.

Calcium stones

Calcium stones are the most common type of kidney stone. They are made of calcium compounds, including calcium oxalate and calcium phosphate. High levels of calcium and oxalate in the body increase the risk of developing calcium stones. There are some medical conditions that can lead to high levels of calcium, including hyperparathyroidism.

Uric acid stones

Uric acid is a waste product that is normally passed out of the body in the urine. Some people have a buildup of uric acid, which can lead to uric acid kidney stones. There are some factors that can increase risk for this type of kidney stone, including:

  • Low urine output
  • Health conditions like gout and Crohn's disease
  • Increased alcohol intake
  • A diet high in animal protein, such as meat, eggs and fish

Struvite stones

Struvite stones are sometimes called infection stones because they can occur with urinary tract infections (UTIs). If struvite stones are large, they are also known as staghorn calculi. These stones require medical treatment because they can cause serious complications. Treatment may include antibiotics and stone removal. Although most stones are more common in men than in women, struvite stones tend to occur more in women who have urinary tract infection.

Cystine stones

This type of kidney stone is made up of the chemical cystine. There is a medical condition called cystinuria, which causes too much cystine in the urine. People with a family history of cystinuria have a greater risk of getting cystine stones.

What's the difference between kidney stones and ureteral stones?

Kidney stones are a buildup of substances in the urine. The substances that make up the stones vary between types of stones, and can even vary within the same type.

Most ureteral stones are kidney stones that have moved out of the kidney into the ureter. The makeup and the type of stone don't change, only the location changes. In general, stones in the kidney don't cause symptoms, but when the stones start to move into the ureter and obstruct the flow of urine, symptoms begin.

Learn more about kidney stones