Kidney Stones

What is a kidney stone? 

Our urine contains minerals and salts.  When the urine has high levels of minerals and salts, stones may form.  When a kidney stone is present you may experience symptoms, or you may experience no symptoms at all. 

What are the different types of kidney stones? 

The four most common types of kidney stones are: 

Calcium Stones: They are the most common type of kidney stones.  If your stone is calcium oxalate, you may be asked to follow a low Oxalate diet.   

Uric Acid Stones: Uric acid crystals do not dissolve well in acidic urine, causing stones to form.  Your urine may be acidic due to having gout, being overweight, chronic diarrhea, type 2 diabetes and a diet that is high in animal protein and low in fruit and vegetables.   

Struvite/infection Stones: People who have a history of chronic urinary tract infections are at the highest risk for these kidney stones.  These kidney stones can become very large and usually require surgical intervention to be treated.   

Cystine Stones: Cystine stones are caused by a rare genetic disorder called Cystinuria.  Too much Cystine in the urine causes kidney stones to form.  These stones usually develop at a young age, usually less than 20 years of age.  These stones tend to reoccur.   

What are the symptoms of a kidney stone? 

Stones in the kidney may not cause symptoms.  If a stone migrates from the kidney into the ureter, the stone may become lodged and can block the flow of urine from the kidney to your bladder.  This causes the kidney to swell (hydronephrosis) and can cause the pain associated with kidney stones.   

Common symptoms of a kidney stone are: 

• A sharp or cramping pain in the back and side, that may move to the lower abdomen and groin. 
• The pain can start suddenly and can come and go. 
• Nausea and vomiting.
• Frequency, urgency and/or burning with urination.
• Urine that is dark red due to blood within the urine. 

How are kidney stones diagnosed?   

There are several tests that may be ordered when you have symptoms of a kidney stone.  These include: 

• Urinalysis which is a collection of urine for testing. 
• X-rays called a KUB. 
• Renal ultrasound. 
• CT scan. 

How are kidney stones treated? 

Treatment of kidney stones depends on the type of stone, its size, its location, and your symptoms.  You and your provider will discuss available treatment options for you.   

Waiting for the stone to pass by itself.

• Smaller stones are more likely to pass than larger stones.  You will be asked to drink 64-100 oz of water per day.  You may also need to take pain medication while you wait for the stone to pass. During this time you may be asked to strain your urine to catch any stones you pass.  
• Some medications can be taken to help a kidney stone pass on its own.  The most common is Tamsulosin, which relaxes the ureter to help the stone pass.

Surgery

• Surgery may be needed if the stone fails to pass on its own, your pain is too severe to wait, and/or the stone is affecting your kidney function.   
• Extracorporeal Shockwave Lithotripsy (ESWL)  
• Cystoscopy with Stent Insertion 
• Ureteroscopic Stone Management 
• Percutaneous Nephrolithotomy (PCNL) 

What are the next steps after having a kidney stone? 

There are several tests that may be ordered to aid in your treatment and in the prevention of future stones.   

• 24-hour urine collection.   
• Other lab tests.
• Renal Ultrasounds
• X-rays to assess your kidneys. 
• Stone analysis. 

If you have formed one stone, you have a 50% chance of forming additional stones within 10 years.  There are changes you can make that may help prevent the formation of the additional stones and/or help your stones to pass spontaneously. 

Fluids: When you do not drink enough fluids, the concentration of your urine increases, causing tiny particles of stone to form in the urine.   

• Increase your fluid intake. This can be accomplished by drinking at least 2.5-3 liters of fluids per day. 
• Use the color of your urine as a guide. It should be pale yellow to clear in color. 
• Water is the best fluid to drink. Drinks to avoid are black teas, dark carbonated sodas, and cranberry juice. 

Diet: Food intake can contribute to the formation of stones as well. Foods to avoid are below: 

• Excess salt and sodium are found in fast food, processed foods, canned soups, cheese, lunch meats, smoked foods, salted nuts, pizza, most canned foods and frozen prepared meals. 
• High animal protein diets, it is recommended that you limit your animal protein intake to less than 6 ounces per day. 
• Too much, or too little, calcium in your diet can also contribute to the formation of kidney stones. For most people it is still advisable to continue your calcium supplement. The best time to take your calcium supplement is with meals. This allows calcium to bind with the oxalate in your diet and decreases the amount of oxalate in your urine. 
• Large amounts of vitamin C can contribute to kidney stones forming.  
• People who have had calcium oxalate stones (which make up about 80% of kidney stones) should avoid too much oxalate in their diet. Foods with high oxalate include spinach, rhubarb, berries, soy, dried beans, chocolate, nuts, nut butters, cranberry juice, sauce, or dried cranberries. See more extensive oxalate chart to follow. 

Citrate: found in real lemon juice, lime juice, and citrus fruits, can decrease your formation of future stones.  It is recommended that you divide ½ cup of real lemon or lime juice between your 2.5-3 liters of water you drink each day.