Kidney Stones
Crystals in urine
Anyone who’s ever had a kidney stone knows how painful one can be. The prevalence of kidney stones in the United States increased from 3.8 percent in the late 1970s to 8.8 percent in the late 2000s but what causes them? Kidney stones usually form when the crystals in the urine and build up to form a hard mass on the inner surfaces of the kidneys. If these crystals remain small, they pass through the urinary system unnoticed but when large enough, they block the flow of urine from the kidney and cause pain. The incidence of kidney stones has been increasing in recent decades, and many experts believe that diet choices and a lack of fluids have contributed to this increase. Still, it’s important to determine the underlying causes so that you reduce the risk of forming more stones in the future. Often you can prevent them by making dietary changes. Remember, a person who has had a stone has a 50 percent chance of forming another one within five years.
A grain of sand
Kidney stones, a painful and often recurring problem, may be as small as a grain of sand or as large as a pebble. There are four major types of kidney stones. The most common type is calcium stone. A struvite stone may form after certain urinary infections. They are often large and may have a characteristic stag’s horn shape. Uric acid stones are formed of a byproduct of protein metabolism. You’re more likely to develop uric acid stones if you eat a high-protein diet or if you have genetic factors that predispose you to the condition or if you’ve undergone chemotherapy. Cystine stones are one of the rarest type, forming in people with a hereditary disorder that causes the kidneys to excrete excessive amounts of certain amino acids. There are chemicals in the urine that normally inhibit the formation of crystals but in patients with kidney stones, however, it appears that they are inadequate to prevent crystals from forming.
Causes a blockage
Not all kidney stones cause symptoms like pain during urination or a persistent urge to urinate. They might be discovered when a person has an imaging study for an unrelated condition. The pain becomes agonizing only when a kidney stone breaks loose and begins to work its way down from the kidneys to the bladder through the tube that connects them, known as the ureter. Someone with a kidney stone may not even know they have one unless the stone is being passed or causes a blockage, or is associated with an infection. Then the most common symptom is an intense flank pain that is usually colicky in nature, fluctuates in intensity and is associated with nausea and blood in the urine. The pain usually starts in the back on one side just under or below the edge of the ribs. As the stone moves down the ureter toward the bladder, the pain may radiate to the lower abdomen, groin and genital structures on that side.
Drinking water
Treating a kidney stone may be as simple as drinking plenty of water and taking pain and antiemetic medications as necessary. Consuming two to three quarts of water a day may be enough to move a stone through your urinary tract, but if it is too big or poses a threat to the kidneys, or if the pain is unrelenting, stronger measures may be taken. Extracorporeal shock wave lithotripsy is used for treating kidney stones and uses shock waves to break the stones into tiny pieces that are then passed in your urine. When lithotripsy isn’t successful or the stone is too large, or in an unsuitable location in the kidney, surgery may be required. Using an instrument called a nephroscope, a surgeon can remove a stone through an incision made in your back. Ureteroscopic stone removal may be used to remove a stone lodged in the ureter. The stone is snared with a small instrument called a ureteroscope that’s passed into the ureter through your bladder.
Certain medications
Preventing kidney stones can often be as simple as making a few lifestyle changes. For people with a history of kidney stones, doctors usually recommend passing at least two and a half quarts of urine a day. To do this, you’ll need to drink about three and a half quarts of fluids every day, and even more if you live in a hot, dry climate. Although most liquids count, water is best. If you tend to form calcium stones, a combination of calcium and oxalate, which is the most common type, your doctor may recommend restricting foods rich in oxalates. These include beets, fish such as herring and anchovies, tea and rhubarb. Research has shown that dairy products may actually prevent calcium stones. Certain medications can control the level of acidity or alkalinity in your urine and may be helpful in people who form certain kinds of stones. As there are four types of stones, the medication your doctor prescribes will depend on the kind of stones you have.
Trusted by thousands of listeners every week, T. Glenn Pait, M.D., began offering expert advice as the host of UAMS’ “Here’s to Your Health” program in 1996. Dr. Pait began working at UAMS in 1994 and has been practicing medicine for over 20 years.