Kidney stones rank right up at the top of the most painful health conditions, according to patients asked to rate their discomfort on a scale of 1 to 10.
Kidney stones are hard pellets composed of minerals — typically calcium — and salts that form inside the kidneys, the organ in the body that produces urine. Also known as renal calculus and nephrolith, kidney stones are a common health issue, affecting 9% to 10% of adults in America, more men than women.
Half of all people who form kidney stones will have another one in the next five to 10 years, and in some cases they can form more rapidly than that, says Dr. Michael Borofsky, a urologist who treats adult patients with kidney stones in the Urology Clinic of the M Health Fairview Clinics and Surgery Center – Minneapolis and an assistant professor in the Department of Urology at the University of Minnesota Medical School.
Because there’s no single cause of kidney stones, there’s no “silver bullet” strategy to prevent them. Physicians typically advise patients to focus on their diet and lifestyle to make their urine less favorable to stone formation.
Read on to learn about the various causes for kidney stones, the types of kidney stones and how to manage their symptoms and treatment.
[READ: How to Prevent Kidney Stones and Improve Kidney Health: Foods to Eat and Avoid]
Causes of Kidney Stones
There’s no one factor that causes kidney stones in most patients. Kidney stones are caused by a variety of factors. They include:
— Dehydration: Inadequate fluid intake can lead to undissolved minerals in the urine — promoting the formation of kidney stones.
— Diets high in salt and animal protein: Consuming excessive amounts of salt, animal protein, dark colas and foods rich in oxalates (from spinach, Swiss chard, beets, rhubarb, almonds, cocoa powder and some types of beans) can increase the risk of mineral buildup and kidney stone development.
— Certain medical conditions: Medical conditions such as obesity, diabetes, hyperthyroidism and certain metabolic disorders could change your urine composition, which could increase the risk of developing kidney stones.
— Certain medications: When taken in excess, medications such as diuretics or calcium-based antacids may increase the likelihood of stone formation.
— Genetic factors: Some genetic traits can make people more prone to developing kidney stones. For example, leaking excessive amounts of calcium into the urine — which can put you at risk for calcium stones — can run in families. If you have a relative who has had kidney stones caused by excessive calcium in the urine, it raises your risk of having the same experience. The closer the familial relationship, the higher the risk.
“The number one cause of kidney stones is dehydration,” says Dr. Ramkishen Narayanan, a board-certified urologist and urologic oncologist and director of the Center for Urologic Health at The Roy and Patricia Disney Family Cancer Center at Providence Saint Joseph Medical Center in Burbank, California.
Healthy, well-functioning kidneys filter about a half-cup of blood every minute, filtering wastes and excess water to make urine. Urine flows from the kidneys to the bladder through two thin tubes called ureters. When the body is hydrated, urine from the kidneys flows through a tube called the ureter — kind of like an internal water slide — en route to the bladder.
When there is too little urine and a lot of waste, chemicals begin to form crystals. These crystals attract other chemicals that form a hard mass resembling a stone inside the kidneys. When large stones leave the kidneys, they can get stuck in the tube that connects the kidney to the bladder.
More specific causes and risk factors for kidney stones can vary based on the type of kidney stone you develop and your individualized health circumstances, including your family history.
Whatever your risk factors, it’s a good idea to do what you can to reduce your chances of developing kidney stones. One of the best things you can do is drink plenty of water.
“One of the best treatments to prevent kidney stones is adequate hydration,” Borofsky says.
[SEE: 8 Ways to Stay Hydrated Besides Drinking Water.]
Types of kidney stones
The four main types of kidney stones and their top causes include:
— Calcium stones include calcium oxalate stones and calcium phosphate stones. Calcium oxalate stones are the most common kidney stone in the U.S., and one of the top risk factors for these is dehydration. Dietary factors, such as consuming too little calcium or too much oxalate, which binds to other minerals to form stones, can also play a role.
— Uric acid stones are a fairly common type of kidney stone in the U.S., caused by excess uric acid — which is a waste product — in the body. Uric acid is formed when the body breaks down purines, a dietary substance found in animal products and some alcohols.
— Struvite stones are a less common type of kidney stone that tends to be caused by upper urinary tract infections.
— Cystine stones are a rare type of kidney stone that typically has genetic risk factors.
[READ: Low Oxalate Diet: Can It Prevent Kidney Stones?]
Kidney Stone Symptoms
For some people, the first clue that they’re experiencing a kidney stone is pain — often in the lower abdomen or groin region. Others may experience kidney stone painlessly, without obvious symptoms.
Symptoms of kidney stones include:
— Pain: Severe pain in the back, side, lower abdomen or groin area
— Urinary changes: Pink, red or brown urine, cloudy or foul-smelling urine and a frequent urge to urinate
— Indirect symptoms: Nausea, vomiting, fever and chills
Some kidney stones do not produce noticeable or painful symptoms. However, that doesn’t mean they’re harmless and may still require medical treatment.
“One misconception patients occasionally have is just because a stone is not symptomatic, it does not need treatment,” says Dr. Vera Trofimenko, a urologist and sexual medicine specialist at St. Joseph Hospital of Orange, California. “This is not always the case.”
Whether they’re painful or not, untreated stones can grow larger, complicating their treatment down the line. Stones can also harbor bacteria or even obstruct the kidney, leading to risks of total and permanent kidney shutdown in some patients, Trofimenko adds.
[READ: Kidney Function Tests: Purpose, Types and Procedure.]
Kidney Stone Pain
Some kidney stones lead to painful or excruciating symptoms. Often, pain from kidney stones implies that the stone has created a blockage that is preventing urine from draining down the ureter, Trofimenko says.
“Since the ureter is a narrow structure, any stone that is large enough to block a substantial part of the caliber of the ureter causes a backup of urine above the level of the stone,” she explains. “This backup is painful because it causes the collecting system of the kidney to stretch and swell as the kidney continues to produce urine, with no (or limited) outlet for drainage.”
Types and locations of kidney stone pain include:
— Flank pain, which refers to pain in the back or side, often just below the ribs, can be associated with kidney stones. It may feel sharp and intense.
— Groin pain can be associated with kidney stones, often while the stone is moving through the urinary tract. This pain may feel like a radiating or spasmodic sensation. While unpleasant, it may also imply that your stone is on the way out of your body.
— Intermittent pain that comes in waves and varies in intensity and location may be directed by the stones’ movement in your body.
Kidney Stone Diagnosis
To diagnose a kidney stone, your doctor may review your symptoms and order blood or urine testing or imaging scans.
Kidney stones are sometimes uncovered as incidental findings on an imaging scan performed for another condition.
If you’re experiencing any symptoms that could indicate a kidney stone, see a health care provider. Even if you don’t have a kidney stone, you could have another health issue that warrants medical attention.
Kidney Stone Treatments
There are a number of treatment options for kidney stones, including medications, medical procedures and in rare cases, surgery. Note that not all kidney stones require treatment, as a majority of stones pass on their own
Kidney stone treatments include:
Medications
Over-the-counter and prescription medications can help treat kidney stone pain, or facilitate kidney stone movement through the ureter, allowing you to eventually pee the stone out of your body, also called “passing” the kidney stone.
Medical procedures
Various medical procedures can help treat kidney stones, and the right one for you will vary based on your stone’s size and location. Some non-invasive or minimally invasive procedures include:
— Extracorporeal shock wave lithotripsy (ESWL) is a non-invasive procedure that uses shock waves to break up kidney stones. An x-ray is also used to help focus on the kidney stones and direct the waves.
— Ureteroscopy is a procedure involving inserting a small tube, or scope, through the urethra, bladder and ureter to reach and collect the kidney stone. Small stones can be collected with a basket device while larger stones may have to first be broken up with a laser.
— Laser lithotripsy is a procedure that’s often combined with a ureteroscopy, in cases where the stone is larger and needs to be disassembled by a laser before it can be taken out.
Surgical InterventionIn rare and severe cases, surgical removal of the kidney stone may be necessary. Percutaneous nephrolithotomy, or PCNL, is a surgical intervention to remove kidney stones.
Kidney Stone Prevention
You can help prevent kidney stones from forming by staying hydrated, eating a nutritious diet and cultivating other healthy lifestyle habits. However, because some stones are caused by your genetic history, you may not be able to avoid them entirely.
Doctor-approved tips for kidney stone prevention include:
— Staying hydrated
— Eating citrus-rich foods, such as oranges
— Reducing sodium intake
— Avoiding dark brown colas
— Limiting oxalate-rich foods — and pairing them with fluids
— Limiting animal protein intake
— Monitoring calcium intake
— Taking prescribed medications
Stay hydrated
Because dehydration is one of the top causes of kidney stones, staying hydrated is a critical for kidney stone prevention. The amount of fluids you should drink daily varies depending on age, level of activity and climate. Most people should consume four to eight glasses of fluids a day.
Narayanan encourages people to get creative with their hydration intake — you don’t have to rely solely on water. “I think that’s one of the biggest misconceptions people have,” Narayanan says. “Fluids can include coffee, it can include tea, it can include juice — it can include all of those things to keep your fluid intake up.”
You can also get hydration from foods. Fruits like watermelon and vegetables like cucumbers are good sources of fluids.
Eat foods high in citric acid
Eating citrus fruits and foods high in citric acid — like lemons, oranges and citrus juices — can help bring down your kidney stone risk, Narayanan says.
“Citrate in the urine is very stone-preventative,” he adds.
Reduce sodium intake
High levels of dietary sodium can increase your risks for dehydration and stone formation. Higher sodium intake causes the kidneys to excrete more calcium into the urine, increasing its calcium concentration. Limiting your sodium intake to 2,000 milligrams a day (or less) has been shown to reduce the risk of forming new kidney stones.
Read food labels to keep track of your sodium intake. And if you’re genetically prone to kidney stones, consider adopting a low-salt diet. On the flip side, salt in electrolyte combinations, like those in popular sports drinks and hydration supplements, can be helpful for hydration, Narayanan says.
Avoid dark brown colas
Dark brown colas have a high fructose content and a high phosphoric acid load that can increase both your calcium and oxalate levels, Narayanan says. Opting for other beverages — even, on occasion, a diet soda, which has less sugar, he adds — will help prevent kidney stones.
“The person who doesn’t drink a lot of water, doesn’t drink a lot of fluids and gets all their fluids from sugary brown colas — that’s what we call a potent combination for stone formation,” Narayanan says.
Limit oxalate-rich foods — and pair them with fluids
Oxalates are natural compounds found in many foods, such as broccoli, spinach, beets, chocolate and nuts. Under normal circumstances, oxalates bind to calcium during digestion in the gastrointestinal tract and are excreted as stool.
However, oxalate that doesn’t bind to calcium can go to the kidney, where it is excreted as urine, Borofsky says. When a person has too much oxalate in the diet, it can cause an excess amount of oxalate in the urine, which can lead to the formation of calcium oxalate crystals and eventually stones, Borofsky says.
You don’t have to avoid oxalate-rich foods altogether — just be mindful of your intake if you’re prone to kidney stones — and increase your fluids to offset the effects.
Moderate animal protein intake
Diets heavy on animal protein — especially without adequate hydration — may increase your risks for uric acid stones, as the body produces uric acid when it breaks down purines. Limiting consumption and increasing hydration may help reduce the risks.
Monitor calcium intake
Even if you’re aiming to reduce your calcium oxalate stone risk, don’t avoid foods containing calcium, as the mineral is essential for helping your body balance out oxalate content. You might want to moderate your intake, however. So, be mindful of how many calcium-rich foods you’re eating and talk to your doctor before taking any calcium supplements.
Take prescribed medicationsIf your doctor has suggested medications to prevent kidney stone formation, such as thiazide diuretics, potassium citrate or allopurinol, take it as prescribed. These medications work in different ways. For example, thiazide diuretics work by reducing the amount of calcium excreted in the urine. Potassium citrate works by making the urine more alkaline, increasing its pH to make it less hospitable to uric acid and cystine stones.
When to Seek Medical Attention
It is important to seek medical attention for kidney stones, as they can lead to severe complications.
“As a community urologist, I strongly recommend that all patients who believe they may have a kidney stone undergo a medical evaluation that includes a urine analysis, physical exam, bloodwork and imaging,” Trofimenko says. “Once this data is available, we make an informed decision about the likelihood of the stone passing on its own, and whether, and for how long it is safe to ‘wait it out.'”
While some people may be safe to wait, Trofimenko adds that others may find themselves in dangerous predicaments that require urgent surgical intervention.
You’ll want to seek immediate medical attention if you experience intense pain, particularly if accompanied by a fever, says Dr. Juan C. Calle, the medical director of the Kidney Stone Clinic in the Department of Nephrology and Hypertension at Cleveland Clinic.
He adds that the most recognizable symptoms of an acute stone event or passage of a stone can include:
— Flank pain that feels severe, acute or colicky
— Flank pain that radiates into the abdomen or groin area
— Pain associated with nausea, vomiting, profuse sweating and uneasiness
— Confusion about whether you are experiencing a kidney stone or urinary tract infection
— An infection
— Problems with urinary flow
“Anyone feeling these symptoms should seek medical attention immediately,” Calle says. “It is often the pain that pushes patients to seek help, usually in urgent care or emergency departments.”
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What Causes Kidney Stones? originally appeared on usnews.com
