LAURA SHAMMAH MS, RDN
KIDNEY STONES, OR RENAL CALCULI, ARE SOLID MASSES MADE OF CRYSTALS. THEY CAN DEVELOP ANYWHERE ALONG YOUR URINARY TRACT, WHICH CONSISTS OF THE KIDNEYS, URETERS, BLADDER, AND URETHRA.
TYPES OF KIDNEY STONES
Not all kidney stones are made up of the same crystals. The different types of kidney stones include:
CALCIUM
Calcium stones are the most common. They’re often made of calcium oxalate, though they can consist of calcium phosphate or maleate. Eating fewer oxalate-rich foods can reduce your risk of developing this type of stone. High-oxalate foods include:
- Potato chips
- Peanuts
- Chocolate
- Spinach
Moderating intake of these foods may be beneficial for people who form calcium oxalate stones. A common misconception is that cutting the oxalate-rich foods in your diet alone will reduce the likelihood of forming calcium oxalate kidney stones. While in theory this might be true, this approach isn’t smart from an overall health perspective. Most kidney stones are formed when oxalate binds to calcium while urine is produced by the kidneys.
Instead, eat and drink calcium and oxalate-rich foods together during a meal. In doing so, oxalate and calcium are more likely to bind to one another in the stomach and intestines before the kidneys begin processing, making it less likely that kidney stones will form.
And even though some kidney stones are made of calcium, getting enough calcium in your diet can prevent stones from forming.
URIC ACID
This type of kidney stone is the second most common. They can occur in people with gout, diabetes, obesity, and other types of metabolic syndrome. This type of stone develops when urine is too acidic. A diet rich in purines can increase urine’s acidic level. Purine is a colorless substance in animal proteins, such as fish and meats.
STRUVITE
This type of stone is found mostly in people with urinary tract infections (UTIs). These stones can be large and cause urinary obstruction. Treating an underlying infection can prevent the development of struvite stones.
CYSTINE
About 1 in 7,000 people worldwide get cystine kidney stones. They occur in both men and women who have the genetic disorder cystinuria. With this type of stone, cystine — an acid that occurs naturally in the body — leaks from the kidneys into the urine
SYMPTOMS AND SIGNS OF A KIDNEY STONE
Kidney stones can cause severe pain. Symptoms of kidney stones may not occur until the stone begins to move down the ureters. This severe pain is called renal colic. You may have pain on one side of your back or abdomen.
In men, pain may radiate to the groin area. The pain of renal colic comes and goes but can be intense. People with renal colic tend to be restless.
Other symptoms of kidney stones can include blood in the urine (red, pink, or brown urine), vomiting, nausea, discolored or foul-smelling urine, chills, fever, frequent need to urinate, and urinating small amounts of urine.
In the case of a small kidney stone, you may not have any pain or symptoms as the stone passes through your urinary tract.
CAUSES OF KIDNEY STONES
Kidney stones are most likely to occur in people between the ages of 20 and 50. A personal history of kidney stones and a family history of kidney stones can increase your risk.
Other risk factors include dehydration, obesity, a diet with high levels of protein, salt, or glucose, a hyperparathyroid condition, gastric bypass surgery, inflammatory bowel diseases that increase calcium absorption, and taking medications such as triamterene diuretics, antiseizure drugs, and calcium-based antacids.
WHAT YOU CAN DO TO HELP PREVENT KIDNEY STONES
- Do not drink soda
- Drink at least 12 glasses of water daily add lemon
- Drink citrus juices, such as orange juice
- Eat a calcium-rich food at each meal
- Limit your intake of animal protein
- Eat less salt, added sugar, and products containing high fructose corn syrup
- Avoid foods and drinks high in oxalates and phosphates
- Avoid eating or drinking anything which dehydrates you, such as alcohol.
- Eat hummus
- Don’t take large doses of vitamin C
(limit to less than 1,000 mg/day).
Studies have shown that drinking ½ cup of lemon juice concentrate diluted in water each day, or the juice of two lemons, can increase urine citrate and likely reduce kidney stone risk, as can apple cider vinegar. A high-sodium diet can trigger kidney stones because it increases the amount of calcium in your urine.
Even though kidney stones can be painful and difficult to deal with, there are many different treatments, medications and procedures available to help manage symptoms.
The two best things you can do to prevent kidney stones are stay hydrated and eat a healthy diet.
