Kidney Stones 101

Pain from a kidney stone may change or shift as the stone moves through the urinary tract. If any of these symptoms worry you, or if pain is so severe that you’re uncomfortable, nauseous or vomiting, or have pain with fever and chills, seek medical attention right away. Also seek immediate medical attention if you have blood in your urine or have significant difficulty passing urine.

Types of Kidney Stones

Knowing the type of kidney stone you have can give clues to the cause of the stone and how to prevent future stones. If you pass one, try to save it so you can bring it to the doctor for analysis. Types of kidney stones include:

• Calcium stones: Calcium stones are the most common type of stone, usually made of calcium oxalate. Dietary factors, high doses of vitamin D, intestinal bypass surgery and certain metabolic disorders can raise the quantity of calcium or oxalate in the urine.
• Struvite stones: These stones form in response to an infection such as a urinary tract infection. Struvite stones grow rapidly and can become large in size quickly, often with few symptoms and little warning.
• Uric acid stones: Uric acid stones are often formed in people who don’t drink enough fluid, lose too much fluid, eat a high-protein diet or have gout. Genetic factors can also increase your risk.
• Cystine stones: These types of stones are caused by cystinuria, a hereditary disorder that causes the kidneys to excrete too much of certain amino acids.

Causes and Risk Factors

Kidney stones often don’t have a single cause. They’re formed when the urine contains more crystal-forming substances (calcium, oxalate and uric acid) than your body is able to dilute successfully. The urine may also lack substances to prevent crystals from sticking to each other, and these factors combine to create a perfect environment for kidney stones.

There are several factors that can raise your risk of kidney stones:

• Family or personal history
• Dehydration
• Certain diets: High protein, sodium and sugar can increase the risk of some kidney stones, especially a high-sodium diet
• Obesity
• Digestive diseases and surgery: Gastric bypass surgery, inflammatory bowel disease or chronic diarrhea can cause alterations to the digestive process. These can affect how you absorb calcium and water, and it can increase the likelihood of stones forming.
• Other medical conditions: Conditions like renal tubular acidosis, cystinuria or hyperparathyroidism can increase your risk, as can certain medications or urinary tract infections.

Diagnosis and Treatment

Kidney stones may be diagnosed using one of several possible tests and procedures. Treatment varies depending on the type, cause, and size of the stone. Small stones with limited symptoms can generally be treated with non-invasive methods:

• Water: Drinking as much as two to three quarts per day can flush the urinary system. Unless instructed otherwise, drink enough to produce clear or nearly clear urine.
• Pain relievers: Passing a small stone can cause discomfort, but mild pain relievers can help.
• Medical therapy: A medication called an alpha blocker may be given to help relax the muscles in the ureter and allow you to pass the stone quickly and with less pain.

For larger stones or stones that cause symptoms, conservative measure might not be enough. Other methods might include:

• Sound waves: Some kidney stones can be broken up using a procedure called extracorporeal shock wave lithotripsy (ESWL), which creates vibrations that breaks the stone into pieces. Side effects are possible.
• Surgery: Certain large stones may require surgery (a process called percutaneous nephrolithotomy) to remove the stone through a small incision in the back.
• Scope: Smaller stones in the ureter or kidney might be able to be removed by a thin tube (ureteroscope) that locates the stone with a camera, then allows it to be broken up with small tools.
• Parathyroid gland surgery: If the stone is caused by an overactive parathyroid gland, the growth from this gland may be removed to stop kidney stones.

Prevention

Prevention of kidney stones comes down to lifestyle changes and medications. Drinking water and making changes to the diet as recommended by your doctor based on the causes of your kidney stones is vital, and your doctor may also prescribe medications based on the kind of stones you have.

If you have symptoms of kidney stones or are at risk, your doctor can provide recommendations for prevention and treatment.

Sources:

“Kidney stones.” The Mayo Clinic. http://www.mayoclinic.org/diseases-conditions/kidney-stones/home/ovc-20319559

“Kidney Stones Health Center.” WebMD. http://www.webmd.com/kidney-stones/default.htm