Kidney Stones: Symptoms, Causes, & How to Avoid Them

13 Science-Backed Ways to Prevent Them With Diet + Lifestyle Strategies

Here’s a fun bit of trivia about a decidedly un-fun topic. The oldest documented human with kidney stones was found in a mummy that researchers believed lived close to 7,000 years ago in pre-dynastic Egypt. (1)

OK, one more: Researchers in one study found a great way to dislodge tiny – emphasis on small – kidney stones is… riding roller coasters. Specifically, 20 rides on the bumpy Big Thunder Mountain Railroad roller coaster at Walt Disney World in Orlando, Florida. (2)

Researchers here “saw kidney stones move from the periphery of their kidney model toward the top of the ureter in many cases,” writes Steph Yin in the New York Times. “Success rates were higher in the back of the roller coaster than the front — 64 percent versus 17 percent — probably because a bumpier ride in the back meant more jostling.” (3)

Here’s the really not-so-fun part about kidney stones: About 10 percent of you reading will experience them at some point in your lifetime, and about 70 percent of those who do will have recurrences. (4)

Mention “kidney stone pain” at your next dinner party and you’re likely to get winces or horror stories. If none of the attendees has suffered through this miserable ordeal, certainly one of them knows someone who has.

Nephrolithiasis, more commonly called kidney stones, affect about five of the population. Kidney stones in men occur twice as often as kidney stones in women. (White males 20 – 30 years old are at the highest risk.) Researchers estimate we spend a whopping two billion dollars yearly to treat them. (5)

Kidney stones can also make your perfectly wonderful day far, far less wonderful. “Passing kidney calculi can be excruciatingly painful for patients, likened to childbirth in intensity,” researchers noted in one study. (6)

Even when you’ve passed a kidney stone, you’re not finished; you have a 50% chance of recurring stones forming within five to seven years. (5)

What Are Kidney Stones?

Kidney stones are hard pebbles that form inside your kidneys. Health professionals deservedly give accolades to crucial organs like your heart or brain, but your kidneys don’t always get that love.

But they should. Among their duties, your kidneys filter toxins from waste chemicals out of your blood and produce urine. Urine leaves your kidneys through the ureters and then into the bladder.

When small mineral crystals in your urine stick together, kidney stones develop. Urine becomes “supersaturated” or overloaded with compounds containing calcium, oxalate, and phosphate. This can result from lots of things including dehydration (more on that in a minute) or a genetic predisposition to over-excrete these ions in your urine. Unfortunately, five to 10 percent of Americans have this predisposition. (5)

Their size and shape differ. Kidney stones can be as small as a grain of sand or – ouch! – as large as a golf ball (although bigger ones are rarer).

When kidney stones are small enough, they can pass through your urinary tract and out of the body on its own, but bigger stones can get stuck in your kidney or ureter. (7) That’s when the trouble starts.

Kidney Stone Symptoms

Symptoms of kidney stones include severe pain, nausea, and vomiting. You might also have to pee very frequently and urgently. The overall feeling might be akin to Dante’s fifth circle of hell, leading to ER visits and hospitalization. (5)

Kidney stone treatment depends on whether your doctor thinks you can pass it alone. If you can, they might suggest a pain medication along with drinking more fluids. (8) More invasive procedures include lithotripsy, which sends shock waves to break up larger stones into smaller pieces, and kidney stone surgery. (9)

Types of Kidney Stones (5)

When someone says they’ve passed a kidney stone, or have kidney stone pain, they’re actually referring to one of several types:

1. Calcium stones

About 80 percent of kidney stones form from calcium oxalate. (10) Hypercalciuria (high calcium in your urine), low urine volume, and hypocitraturia (low citrate excretion) all contribute to calcium stones. Dietary oxalate intake from foods be among the culprits. Oxalates occur in many plant foods, but some are higher than others. Food that cause kidney stones include high-oxalate foods like spinach, beets, and rhubarb, which can increase urinary oxalate excretion and help develop calcium oxalate stones.

“Calcium oxalate kidney stones can result from excessive oxalates being absorbed through the gut and then binding with calcium in the urine and precipitating out to form the stones,” writes Dr. Jonny Bowden in The 150 Healthiest Foods on Earth. “Unfortunately, cooking doesn’t do very much to reduce them. Oxalates should be watched by people with hyperoxaluria, a rare, inherited metabolic disorder that often causes the stones.” Bowden notes this is not a problem for 99 percent of people.

2.     Uric acid stones

When your urinary pH is too low (the average pH is six), (11) several products of purine metabolism can build up, leading to uric acid stones. (12) About 15 – 20 percent of patients with uric acid stones have a history of gout.

3.     Cystine stones

These stones primarily form with cystinuria, an autosomal recessive disorder affecting one in 15,000 American adults that accounts for only one percent of patients with kidney stones. Cystinuria occurs equally in males and females (though males are more severely affected). Urinary tract infection and obstruction are common, and kidney stone recurrence often occurs every one to four years.

4.     Struvite stones

Struvite stones commonly occur in patients with recurrent urinary tract infections. They occur three times more often in women than men (since urinary tract infections are more common in women). They are typically very large and even fill the renal pelvis. Struvite stones grow quickly and they often grow back after surgical removal because infected fragments of stone linger.

What Causes Kidney Stones?

Yes, kidney stones can be hereditary, and if you’ve had one, it maybe paved the path (yes, bad pun) for another one. Yet even under the worst conditions, you have plenty of ways to reduce occurrence or recurrence of kidney stones. While kidney stone formation often becomes multifactorial, a few culprits underlie their development.

Diet and lifestyle

Foods that cause kidney stones? Pretty much any staple of the Standard American Diet is fair game.

Studies show over the past 30 years, stone formation has increased among both sexes (13), and I believe our increasingly crapola processed diet, sedentary living, and neglecting things like stress management and quality sleep are tops to blame. And research supports me:

• Soda drinkers, be warned: One study with 14 males and 31 females found cola causes unfavorable changes in the risk factors associated with calcium oxalate stone formation. (14)
• Researchers conclude excessive consumption of carbohydrates (especially simple ones) become a risk factor for kidney stones. (15)
• Having a Game of Thrones marathon while munching salt and vinegar potato chips might sound like fun, but consider swapping them out for some sprouted almonds: Studies show high sodium intake increases urinary calcium excretion, making kidney stones more likely. (5)
• While low-carbohydrate diets often get accolades, if you have a familial history of kidney stones or if you’ve had them yourself, you might want to reconsider: Although it only involved 10 healthy adults, one six-week study found a high-protein, low-carb diet could increase kidney stone risk while reducing your body’s ability to absorb calcium. (16)
• Some prescription drugs including antibiotics and laxatives can increase your risk for stones. (17) Never go off any drugs without your doctor’s permission, but talk with him or her if you’re concerned a particular medication might create or exacerbate kidney stones.
• Studies show chronic stress can potentially increase kidney stones. Researchers found elevated stress played a role in patients who passed two or more stones a year. (18)

Metabolic issues

Simply put, overweight folks and people with chronic illnesses are more susceptible to kidney stones. That makes sense when you consider inflammation underlies kidney stones (19), and almost every disease on the planet (including obesity) has an inflammatory component. Among the culprits that could increase your risk for kidney stones:

• Diabetes: Studies show insulin resistance, which paves the path for Type 2 diabetes, could lead to deficient ammonium production in your kidneys that lowers urinary pH, creating the perfect environment to form kidney stones. (20)
• Obesity: Epidemiologically, a greater body mass index (BMI), higher weight, bigger waist circumference, and major weight gain are independently associated with an increased risk of kidney stone formation. (21)
• While the studies are older, three epidemiological surveys found a statistical association between arterial hypertension and kidney stone disease.(22)

 

Dehydration

Drink up: Dehydration may be the biggest risk factor for kidney stones and the easiest one to prevent.

Filtered water always works best, but black coffee or green tea can also help. In one study with middle-aged women, coffee, tea, and wine prevented kidney stone disease, whereas grapefruit juice promoted kidney stone disease.

Men got those same benefits, though beer also reduced kidney stones and apple juice increased the risk of kidney stones. (23) [No, that does not give you license to heavy-hit the chardonnay or pilsner.]

How to Avoid Kidney Stones – 13 Ways to Prevent Them

The best way to evaluate your stone risk and determine what might be causing them is a 24-hour urine collection and analysis, and researchers recommend two 24-hour urine collections for the initial evaluation to determine accuracy and variability. (5)

If you suffer from frequent kidney stones, please talk with your urologist about treatments. Living in pain or hoping that the stone will pass are not ideal solutions.

At the same time, just because you’ve had one in the past or have a familial history doesn’t mean you need to accept your fate, and foremost among ways to prevent kidney stones or their recurrence is by the way you eat and live.

“Kidney stone prevention should be individualized in both its medical and dietary management, keeping in mind the specific risks involved for each type of stones,” researchers in one study note. “Recognition of these risk factors and development of long-term management strategies for dealing with them are the most effective ways to prevent recurrence of kidney stones.” (5)

While there’s no one standard kidney stone diet, these 13 dietary and lifestyle modifications can dramatically help long-term management strategies.

1. Start your day with lemon water

Bowden says “according to naturopathic physician Andrew Rubman, N.D., half of a lemon daily raises the level of citrate in the body, which may help in fighting kidney stones. (Note: Other citrus juices do not have this effect; grapefruit juice has the opposite effect and should be avoided if you’re prone to kidney stones.)”

2. Step up the color

Research shows an antioxidant-rich diet can reduce stone episodes. (19) That’s one among many reasons a colorful array of vegetables and low-sugar fruits like berries and avocado should be in your meal plans.

3. Keep a food journal

Nutritional assessment to prevent or treat stones includes a 24-hour food recall, food record diet history, and food frequency questionnaire. (5) You can do this yourself with a daily food journal, which doubles as a way to maintain accountability and pinpoint troublemaking foods. As a “bonus,” researchers found people who wrote down everything they ate in one study lost twice the weight of those who didn’t. (24)

4. Dial down fructose

This number-one sugar offender is bad news all-around. Among its havoc, fructose ramps up uric acid and inhibits its urinary excretion. (25) You probably got rid of high-fructose corn syrup (HFCS) way back, but even too much higher-fructose fruit can create problems if you’re particularly susceptible.

5. Easy with calcium supplements

Getting calcium from foods including leafy greens and nuts is just fine and shouldn’t exacerbate kidney stone development, but supplements are another story. A massive 12-year follow-up study with 903,849 folks found 864 cases of kidney stones. Dietary calcium was inversely associated with risk for kidney stones, while intake of supplemental calcium was positively associated with risk. In other words, dietary calcium appears could decrease risk for kidney stones, whereas calcium supplements could increase risk. (26)

6. Get more sleep

This might be the oddest reason you’ve heard to get eight hours of quality uninterrupted sleep, and it’s worth considering. Researchers found sleep position could be a simple, non-invasive way to improve kidney stone passage or even how to prevent kidney stones.

“In a clinical setting, asking patients to spend more time in a specific sleep position might represent an effective means of not only preventing stone formation, but also in assisting stone passage,” researchers note. “One might apply this concept by asking a patient who is at risk of stone formation (but currently stone free) to sleep on their contralateral side and an individual trying to pass a stone fragment to sleep on their ipsilateral side.” (6) (They add this might not be easy to do.)

7. Fit in regular physical activity

You don’t need another reason to get moving, but here’s one anyway: Exercise helps the body absorb calcium by increasing blood flow to the intestines. (27) Weight resistance and high-intensity interval training (HIIT) are great, but so are things like yoga and walking that get your blood flowing.

8. Step away from the salt shaker

Excess sodium – which typically occurs when you eat too many processed foods and sprinkle salt on everything – potentially increases calcium excretion, creating kidney stones in the bargain. Consider supplementing with potassium citrate (citrate prevents calcium crystal formation and growth), and step up potassium-rich foods like avocado and spinach.

9. Drink two liters of filtered water every day

Dehydration means low urinary output, which could make your urine supersaturated and pave the way for kidney stones. (28) Keep a canteen nearby with filtered water and sip throughout your day. Aim for about two liters total.

10. Increase magnesium

This underrated mineral might play a big role in kidney stone treatment. One study found magnesium ions tends to destabilize calcium oxalate, suggesting they might inhibit kidney stones. (29) Another found magnesium hydroxide could reduce stone recurrence rate. (30) Leafy greens and nuts provide some magnesium, but to get therapeutic amounts you’ll probably need to supplement. An Epsom salts bath before bed can also boost magnesium and help you unwind after a long day.

11. Balance fat-soluble nutrients

Vitamin D supplements deservedly get glory, but taking high amounts can knock other fat-soluble vitamins out of balance. “In someone with kidney stones, vitamin A deficiency, vitamin K2 deficiency, and vitamin D excess are all prime suspects to be considered in terms of both absolute amounts and proportions between the vitamins,” writes Registered Dietitian Laura Schoenfeld. (31) One study among 36,282 healthy postmenopausal women found calcium with vitamin D supplementation increased the risk of kidney stones. (32)

12. Eat more wild-caught fish

Kidney stones were virtually absent among the Inuits of Greenland, who ate fresh fish as a dietary staple. Coincidence? If wild-caught fish isn’t among your go-to foods, consider fish oil. Researchers find supplementing with eicosapentaenoic acid (EPA) – one of the two primary omega-3 fatty acids in fish and fish oil – leads to reduced calciuria. (33)

13. Be mindful about protein

Studies show reducing protein can possibly help people at risk for kidney stone disease. (This probably isn’t a concern if you don’t have that risk, although moderating protein intake is always a good idea.) The evidence isn’t conclusive: Researchers found cohort studies conflicting, and only two randomized-controlled trials have evaluated the hypothesis that reducing animal protein could prevent kidney stone recurrence. (15)