Kidney stones can form when your urine has high levels of certain minerals and salts. They come in many different types and colors.
Calcium stones (calcium oxalate and calcium phosphate) are the most common type, resulting from too much calcium in your urine.
Other types of stones include the following:
- Uric acid stones, resulting from acidic urine
- Struvite/infection stones (uncommon), related to chronic urinary tract infections (UTIs)
- Cystine stones (rare), resulting from high amounts of cystine in the urine
- Low urine volume — caused by dehydration from activity or not drinking enough fluids
- Diet — too much calcium intake; over consumption of animal protein, such as beef, fish, chicken and pork; eating too many foods rich in oxalate
- Bowel conditions that cause diarrhea, leading to low urine volume
- Certain medical conditions
- Some medications and/or calcium and vitamin C supplements
- Family history of stones
- “Silent” kidney stones with no symptoms
- Sudden pain while the stone is passing
- Blood in the urine (hematuria)
- Sudden abdominal or side pain
An X-ray taken during a health exam may find a “silent stone.” When pain occurs, an ultrasound or a CT scan may diagnose a stone.
The type of stone will determine treatment. Options may include the following:
- No treatment: Let the stone pass on its own.
- Medication: Your doctor may prescribe medications to improve the chance that a stone will pass.
- Lithotripsy: Your doctor will break apart the stone using shock waves. Firing shock waves repeatedly on the stone breaks it into small pieces. Over a few weeks, these smaller pieces of stone will pass through the urine.
Surgery may be needed if …
- The stone fails to pass on its own.
- The pain is extreme.
- The stone affects kidney function.
Surgery is recommended if …
- Stones cause repeated infections in the urine or block urine flow from the kidney.