Carolinas HealthCare System

What Are Kidney Stones?

Kidney stones are fairly common. They are small, solid objects that can build up inside the urinary tract. When salts and minerals in the urine become overly concentrated, these crystals can form over the course of a few weeks or months.          

If the stone is small, it can usually pass through the urinary tract and out of the body on its own, with minimal pain. If the stone is large, it can be quite painful. A large stone may block the flow of urine and cause other urinary tract problems.

Several kinds of kidney stones exist, each with many different causes, and treatment ranges from an increase in water consumption with pain medication, to surgery or other medical procedure.

Types and Causes of Kidney Stones

Calcium stones: Most kidney stones are called calcium stones and are made of calcium compounds, especially calcium oxalate. Calcium phosphate and other minerals may also be present in this type of kidney stone. Conditions that cause high calcium levels in the body, such as hyperparathyroidism, increase the risk of calcium stones.

Struvite stones: Struvite stones are also called infection stones, because they occur with kidney or urinary tract infections (UTI). Also called staghorn calculi, they can be serious, because they are often fairly large. Medical treatment, including antibiotics and removal of the stone, is usually needed for struvite stones.

Uric acid stones

A small percentage of kidney stones are made of uric acid, a waste product that typically passes from the body during urination. You are more likely to have uric acid stones if you have low urine output, eat a diet high in animal protein, such as red meat, an increase in alcohol consumption, have gout or have been diagnosed with inflammatory bowel disease. Certain medicines may prevent or dissolve uric acid stones.

Cystine stones: Less than 1 percent of kidney stones are made of a chemical called cysteine. They may be treated with medicine or a surgical procedure.

Symptoms of Kidney Stones

Often, small stones have no symptoms. Larger stones, though, can block the urinary tract and cause symptoms like: 

  • A sharp pain that starts in the side or back
  • Pain that spreads to the lower belly and groin as stones move through the urinary tract
  • Pain that comes and goes in waves
  • Blood in the urine (appearing red or brown)
  • Nausea and vomiting
  • Needing to urinate often or urgently
  • Fever or chills

The physicians at Levine Children’s Hospital in Charlotte, NC are skilled in the treatment of all types of kidney stones and are equipped to find the right treatment for you.