Kidney Stones Overview
Kidney stones are hard mineral deposits that form inside the kidney, often when the waste products in urine become too concentrated and crystallize. Passing kidney stones can be very painful. The pain may change as the stone moves through your urinary tract.
Kidney stones seldom cause permanent damage.
Types of kidney stones include:
- Calcium stones. Most kidney stones are of calcium, usually calcium oxalate. Oxalate comes from some fruits and vegetables, nuts and chocolate, and is made by your liver; vitamin D, intestinal bypass surgery, and some disorders can also increase the amount of calcium and oxalate in your urine.
- Struvite stones, which can grow quickly and quite large in response to infection.
- Uric acid stones, caused by dehydration, a high-protein diet, or gout; there may also be a genetic predisposition.
Kidney Stones Risk Factors
Kidney stones form when there is not enough water in your urine to keep the waste products removed from your blood by your kidneys in solution, causing the waste products to crystallize out of the urine. Your urine may also lack the chemicals that inhibit these crystals from adhering to one another, allowing them to become kidney stones.
Risk factors include:
- Personal and family history
- Age 40 or older
- Being male
- Chronic dehydration
- High-protein, high-sodium, and high-sugar diets
- Digestive diseases and surgery
- Certain urinary tract infections
- Metabolic disorders
Kidney Stones Symptoms
Often, kidney stones have no symptoms until they pass from the kidney to the ureter on their way to the urinary bladder. Symptoms include:
- Severe local pain
- Pain that spreads downward toward the groin
- Painful urination
- Pink, red, or brown urine
- Nausea and vomiting
- Persistent need to urinate
- Fever and chills
Seek immediate medical attention if your pain:
- Is so severe you can't stay still or find a comfortable position
- Is accompanied by nausea or vomiting
- Is accompanied by fever and chills
Kidney Stones Diagnosis
Tests to diagnose kidney stones include:
- Blood tests to reveal excesses of some of the constituents of kidney stones, like uric acid and calcium
- Urine tests to reveal stone-forming minerals or deficiency of stone inhibitor.
- Imaging, like computerized tomography (CT)
- Analysis of stones caught in a strainer
Kidney Stones Treatment
Most kidney stones require only minimal treatment. Drinking two or three liters of water a day may flush them from your urinary system, and provide enough urine to prevent waste products from crystallizing into stones. The pain caused by passing a small stone can be alleviated with pain relievers like Advil®, Tylenol®, and Aleve®.
Stones that are too large to pass or are causing bleeding, kidney damage, or infection require more aggressive treatment, including:
- Extracorporeal shock wave lithotripsy: It uses a strong sonic wave to break the stones into tiny pieces that can be passed. It is a noisy, somewhat painful procedure, so you may be sedated or lightly anesthetized.
- Surgery: If the shock waves are unsuccessful or the stone is very large, it may be surgically removed through a small incision in your back.
- Removal: A thin scope is inserted through your urethra and bladder to remove a stone from your urethra or kidney, possibly after crushing it.
- Parathyroid gland surgery: A benign parathyroid tumor can cause overproduction of parathyroid hormone, which increases blood calcium, resulting in calcium kidney stones. Removal of the tumor stops this overproduction.