Kidney Stones. This reference summary will help you understand kidney stones and how to treat and prevent them. Kidney

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1 Introduction A kidney stone is a solid piece of material that forms in the kidney from substances in the urine. Kidney stones are fairly common. Although kidney stones can be painful, they are treatable. This reference summary will help you understand kidney stones and how to treat and prevent them. Kidney Anatomy Most people are born with two kidneys. Kidneys are organs in the middle to lower back on each side of the spine. The kidneys form urine. The urine then flows through tubes called ureters to the bladder, where it is stored. The main function of the kidneys is to filter harmful chemicals known as toxins from the blood. The toxins leave the body in the urine. Kidneys Ureters When the bladder is full, people feel the urge to urinate. The urine leaves the body through the urethra. Bladder Urethra Kidney stones vary in size and shape. They can Urinary System range from the size of sand particles to the size of a golf ball. Some stones, known as staghorn stones, can fill the entire kidney. These are usually caused by infections. Kidney stones can be smooth or jagged. 1

2 Kidney stones form when crystals in the urine stick together. These crystals are made from chemicals in the urine. Most stones are formed of calcium, which can be found in dairy products. Other chemicals such as oxalate, uric acid and cystine can also cause stones. Kidney and urine infections may cause stones. Symptoms The most common symptom of kidney stones is pain in the side and back. The pain is usually severe. It comes in spasms and may spread to the groin. This pain happens when a small stone gets stuck in one of the ureters on its way to the bladder. A kidney stone in the ureter causes urine flow through the ureter to slow down. Urine may back up and cause swelling in the ureter and kidney. This can cause pain and long term damage if not treated quickly. Infections may also happen. An infection may result in fever, burning during urination, nausea and vomiting. Blood in the urine is another symptom of kidney stones. Diagnosis Your health care provider will ask about your medical history. They will perform a physical exam. A simple x-ray of the abdomen, known as a KUB or Kidney, Ureters and Bladder, can help detect the stone. An IVP may also be done. This is a test where dye is injected into a vein and x-rays are then taken of the abdomen to see how quickly the kidneys filter the dye into the urine. An IVP also shows the shape of the kidneys, ureters and bladder. An IVP can show the exact location of kidney stones. CT scans are the best way to detect a kidney stone and its location. Ultrasounds of the abdomen may also be needed. Blood work and urine samples may be needed. These can help your health care provider check for infection, blood in the urine and high levels of chemicals that may cause kidney stones. 2

3 Treatment Depending on your symptoms, as well as the size and location of the stone, your health care provider may wait and see if the stone comes out on its own. You will probably be given enough medication to help with severe pain. You will be asked to drink a lot of fluid, about 12 eight ounce glasses, to help flush the stone. This is known as expectant therapy. If the symptoms are not severe, medication can be given in some cases to change the composition of the urine and help dissolve the stone. This takes a long time and is not a good option in cases of severe pain or urinary obstruction. If the pain persists and you have not been able to pass the stone, further treatment may be needed. Your health care provider may perform ESWL, or extracorporeal shock wave lithotripsy. During this procedure, you will be asked to lie down on a soft mattress. You may be placed in a tub filled with water, depending on the apparatus used for ESWL. This was more common in the past. A machine then sends shock waves to the stone. This causes the stone to crumble and become smaller. The stone then becomes easier to pass in the urine. ESWL may need to be repeated. ESWL is usually an outpatient procedure. You will probably be able to go home the same day of the procedure. You will be asked to strain your urine during expectant therapy or after lithotripsy to see if the stone or sand ESWL has passed. Give the stone or sand to your health care provider so they can figure out the chemical makeup of the stone. That way you can make changes to your diet to help you prevent future kidney stones. Patients who undergo ESWL may be more likely to develop hypertension and diabetes than patients who do not. Some stones are very hard and are not affected by the shock waves. If ESWL is not successful, or if your health care provider does not suggest it, other procedures can be performed to take the stones out. 3

4 Your health care provider can go through the urethra and bladder and into the ureter using a scope. He or she can then find the stone and take it out. This is known as ureteroscopic stone removal. It is usually an outpatient procedure. Sometimes the stone is too big to remove and is broken into smaller pieces. In this case, a surgical tool or a small laser is guided through the urethra, into the bladder and then into the ureter. Another option is called percutaneous nephrolithotomy, or PCNL. PCNL uses small telescopes and surgical tools to remove large or very hard stones. It is less invasive than an open operation, but you may still have to stay in a health care facility after the procedure. If ureteroscopic stone removal or PCNL are not possible, the kidney itself can be opened up surgically through the back to take the stones out. This is called an open operation. It is an inpatient procedure. You may have to stay in a health care facility after the operation. Prevention You can prevent kidney stones by making simple changes in your diet. Drinking lots of fluid helps keep the urine flowing and decreases the chance of stones forming. Some liquids cause people to get dehydrated and should be limited. These include beverages that contain alcohol and caffeine. Dietary changes can be helpful in decreasing your chance of stone formation. If you have calcium stones, you should limit your intake of dairy products, such as milk and cheese. If you have oxalate stones, you should limit your intake of colas, chocolate and peanuts. If you have uric stones, you should limit your intake of meat, chicken and anchovies. If you have cystine stones, you should limit your intake of fish. Depending on the kind of stones you have, some medications may be given to decrease the specific stone forming compounds in the urine or to decrease the ability of the urine to form stones. These medications should be taken as prescribed by your health care provider. You should schedule regular follow-up visits with your health care provider. 4

5 Summary A kidney stone is a solid piece of material that forms in the kidney from substances in the urine. Kidney stones are fairly common. They can range from the size of sand particles to the size of a golf ball. The most common symptom of kidney stones is pain in the side and back. The pain is usually severe. It comes in spasms and may spread to the groin. Kidney stones form when crystals in the urine stick together. These crystals are made from chemicals in the urine. Depending on your symptoms, as well as the size and location of the stone, your health care provider may wait and see if the stone comes out on its own. Treatment options for kidney stones include medication, extracorporeal shock wave lithotripsy, ureteroscopic stone removal, percutaneous nephrolithotomy and open surgery. You can prevent kidney stones by making simple changes in your diet. Drinking lots of fluid helps keep the urine flowing and decreases the chance of stones forming. 5