Nephrologist, Davita Kidney Specialists of Alabama.
What are Kidney Stones?
Kidney stones are crystalline deposits of minerals that form in the urinary tract. Most kidney stones result from the deposition of calcium in combination with phosphate or oxalate. Uric acid or cysteine stones are rarer. The Southeastern part of the United States forms the “stone belt” of America. The hot weather, genetic factors, poor fluid intake, a diet rich is salt, animal protein and oxalate are some of the factors that contribute to this increased prevalence.
Symptoms of a kidney stone
- Severe pain in the side and back, below the ribs radiating to the lower abdomen and groin. There can be associated nausea and vomiting.
- Pain on urination, urgency and frequency
- Difficulty to pass urine
- Pink, red or brown urine that can indicate mild bleeding
- Cloudy or foul-smelling urine
- Fever and chills if an infection is present
If any of the above symptoms are severe or persistent, make an appointment to see your doctor. The good news is that most stones do not cause any permanent damage to the kidney function.
Types of kidney stones
These the most commonly seen kidney stones, usually in the form of calcium oxalate or phosphate.
Struvite stones form in response a urinary tract infection with certain bacteria. These stones can grow quickly and become quite large, sometimes with few symptoms or little warning.
Uric acid stones
Uric acid stones can form in people who don’t drink enough fluids and eat a high-protein diet. It can also be seen in patients who have gout. Certain genetic factors also may increase your risk of uric acid stones.
These stones form in people with a hereditary disorder that causes the kidneys to excrete too much of certain amino acids (cystinuria).
Risk factors for stone formation
Calcium oxalate or phosphate account for a majority of kidney stones. Oxalate is a naturally occurring substance found in food. Some fruits and vegetables, nuts, chocolate and sweet tea, have high oxalate levels. Avoiding these foods after discussing with your doctor can help reduce stone formation. Increased salt intake enhances calcium excretion in the urine and therefore increased stone formation. Dairy included with your meal helps bind the oxalate in the gut preventing its absorption and reducing its excretion in the kidneys. Eating a diet that’s high in protein can result in uric acid stones especially in patients with gout. Dietary counseling is the corner stone in preventing kidney stone formation.
Poor fluid intake of dehydration
Not drinking enough water each day can increase your risk of kidney stones. People who live in warm climates and those who sweat a lot may be at higher risk than others. The poor intake of fluid results in more concentrated urine that promotes stone deposition of forming salts.
High body mass index (BMI), large waist size and weight gain have been linked to an increased risk of kidney stones.
Family or personal history
If someone in your family has kidney stones, you’re more likely to develop stones, too. And if you’ve already had one or more kidney stones, you’re at increased risk of developing another. This is because some patients have a genetic mutation that can cause them to excrete high levels of calcium in the urine.
Kidney stones are most common in adults age 40 and older, though kidney stones may occur at any age.
Men are more likely to develop kidney stones, although an increasing number of women are developing kidney stones.
Digestive diseases and surgery
Gastric bypass surgery, inflammatory bowel disease or chronic diarrhea can cause changes in the digestive process that affect your absorption of calcium, oxalate and water, increasing the levels of stone-forming substances in your urine.
Other medical conditions
Diseases and conditions that may increase your risk of kidney stones include renal tubular acidosis, cystinuria, hyperparathyroidism, certain medications and some urinary tract infections.
Kidney Stone Prevention
If you are a recurrent stone former you can be evaluated for this condition. Your Nephrologist or Urologist can do 24 hour urine studies to determine factors that put you at risk for kidney stones. They can counsel you about key dietary changes that can reduce the risk of stone formation. Certain medications can help reduce the calcium content of your urine and reduce frequency of stone formation. Irrespective of the cause of kidney stones there are some general measures that can be practiced to prevent the severity and frequency of kidney stones.
Drink plenty of water
Drinking extra water dilutes the minerals in urine that lead to stones. The goal is to drink enough to make at least 2 liters of urine a day, which is roughly eight standard 8-ounce cups. Adding a little lemon makes the urine environment unfavorable to stone formation. Your nephrologist may recommend citrate to prevent stone formation. The answer is simple ‘Drink Drink Drink!”
Include calcium with each meal
Calcium in your diet will bind oxalate and reduce kidney stones. This is counter intuitive to the belief that eating more calcium will cause stones. Ideally, obtain calcium from foods, and not from calcium supplements Add some yogurt, buttermilk or a piece of cheese with your meal for the additional source of calcium.
Reduce salt in the diet
A high-sodium diet can trigger kidney stones because it increases the amount of calcium in your urine. So a low-sodium diet is recommended for the stone prevention. Current guidelines suggest limiting total daily sodium intake to 2,000 mg. This will also be good for your blood pressure and heart health.
Limit animal protein
Eating too much animal protein, such as red meat, poultry, eggs, and seafood, boosts the level of uric acid and could lead to kidney stones. A high-protein diet also reduces levels of citrate, the chemical in urine that helps prevent stones from forming. If you’re prone to stones, limit your daily meat intake to a quantity that is no bigger than a pack of playing cards. This is also a heart-healthy portion.
Avoid stone-forming foods
Beets, chocolate, spinach, rhubarb, tea, and most nuts are rich in oxalate, and colas are rich in phosphate, both of which can contribute to kidney stones. If you suffer from stones, your nephrologist may advise you to avoid these foods or to consume them in smaller amounts.