Kidney Stone Management
Kidney stones, also called nephrolithiasis, are hard clumps of solid chemicals in urine that form in the kidneys. According to the National Kidney Foundation, more than 500,000 Americans visit emergency rooms for kidney stone pain and other problems each year.
What Are Kidney Stones?
Kidney stones can be as small as a grain of sand or as large as a pea. Some kidney stones stay inside the kidneys, but some move into the ureter, the tube that passes urine. Small stones may pass out of the body without issue. Larger ones can cause extreme pain as they pass. Stones that become lodged in the kidneys or ureter can block the flow of urine, leading to potentially serious complications, including kidney infection or damage. Kidney stones also increase the risk of developing chronic kidney disease.
Types of Kidney Stones
There are four main types of kidney stones, classified by what they are made of. Most kidney stones are made up of calcium, a mineral, or a chemical called uric acid. The other two materials in kidney stones include:
- Cystine, an amino acid that can build up in the urine of people who have cystinuria, a rare inherited metabolic disorder
- Struvite, a mineral that forms in alkaline urine often as a result of a urinary tract infection
What Causes Kidney Stones
People can get kidney stones when minerals normally present in urine become highly concentrated. Common risk factors include:
- certain medications such as water pills, known as diuretics, or antacids containing calcium
- dehydration
- diabetes
- diets high in sodium or sugar
- digestive diseases such as inflammatory bowel disease
- genetic factors
- hyperparathyroidism, caused by overactive parathyroid glands
- inflammatory diseases that affect the joints, such as gout
- obesity
- recurrent urinary tract infections
Signs and Symptoms of Kidney Stones
Smaller kidney stones do not always cause symptoms and may pass without causing significant pain or damage. If symptoms do occur, they may include:
- dizziness or lightheadedness
- fever and chills
- nausea and vomiting
- urine that is bloody, pink or cloudy or has a foul odor, which are signs of possible infection
People who have experienced kidney stones say they feel sharp, severe pain in their abdomen or lower back.
How Are Kidney Stones Diagnosed?
Kidney stones are diagnosed with laboratory tests and other procedures including:
- blood and urine tests that measure mineral levels
- imaging studies, such as ultrasounds, X-rays or CT scans
- kidney stone analysis to determine their composition
Treatments for Kidney Stones
Treatment for kidney stones depends on the cause, type, size and location. Options that can prevent kidney stones may include:
- dietary changes such as avoiding calcium-rich foods like dairy when eating oxalate-rich foods, such as chocolate, nuts, seeds, spinach and sweet potatoes. Calcium and oxalates can combine to form kidney stones.
- eating less salt and animal protein
- increasing fluid intake to help existing stones pass out of the body and prevent new ones from forming
- taking pain relievers
- therapies to balance the pH levels, the acidity and alkalinity, of urine
For large kidney stones or ones that block the urinary tract, procedures to remove them or break them into smaller pieces may be required. Options may include:
- cystoscopy or ureteroscopy, in which a thin, flexible instrument with a light — called either a cystoscope or ureteroscope — is used to examine the urinary tract, locate a kidney stone and break it up
- percutaneous nephrolithotomy, or nephrolithotripsy, in which a thin, lighted tube called a nephroscope is inserted directly into the kidney to find and remove or break up stones
- extracorporeal shock wave lithotripsy, a procedure that uses high-energy sound waves delivered from outside the body to break up kidney stones