Be Kidney Healthy

Your kidneys are very important organs in your body. Their role is to filter your blood of waste products and excrete waste and water as urine. Everything you eat and drink affects the level of nutrients and materials that get into your bloodstream. Therefore, diet plays an important role in the health and function of your kidneys.

kidney stonesWhat Is a Kidney Stone?

Kidney stones are hard formations inside the kidneys that typically consist of insoluble calcium compounds. These stones may be as small as a grain of sand or as large as a golf ball. Most stones break off and pass out of the body through the urine naturally.

Doctors can help you prevent stones by prescribing certain medications. However, if you already have a stone, it can usually be flushed out by drinking large amounts of water. If it cannot be passed on its own, the doctor can remove the stone through surgery or breaking it up using sound waves. There is no medication available that can be used to actually dissolve the stone.

What Causes Kidney Stones?

Kidney stones often do not have a definite single cause, although several factors may increase your risk for developing kidney stones, including:

  • Not drinking enough water. The Institute of Medicine set general recommendations for women at approximately 2.7 liters (91 ounces) of total water from all beverages and foods each day. For men, an average of approximately 3.7 liters (125 ounces) of total water from all beverages and foods each day is recommended.
  • Regularly consuming dark-colored sodas high in phosphorous.
  • Taking calcium supplements at levels that exceed the recommended daily allowance.
  • Genetic or metabolic disorders
  • Chronic urinary tract infections
  • Not getting enough physical activity

Are There Different Types of Kidney Stones?

There are many types of kidney stones. Knowing what type of kidney stone you have can help determine the cause and avoid the development of future kidney stones.

Calcium stones are the most common. These stones occur when too much calcium is filtered through your urine. Oxalate from the diet or produced by the liver can bind with calcium and form an oxalate stone. Dietary factors, high doses of vitamin D, and several metabolic disorders can increase the concentration of calcium oxalate in urine, potentially leading to the development of kidney stones.

Other types of kidney stones include struvite stones, which occur in response to an infection; uric acid stones, which generally occur in those who do not drink enough fluids, lose too much fluid, eat too much protein, or have gout; and cystine stones, which result from a hereditary disorder that causes the kidney to excrete too much of the amino acid cystinuria.

What are Some Signs That I Might Have a Kidney Stone?

Kidney stones do not always present signs or symptoms in their early stages. Symptoms often occur when kidney stones move around within your kidney or pass into your ureter. Signs and symptoms include:

  • Pain in kidney area (middle of back) or lower abdomen
  • Nausea or vomiting
  • Fever, chills, and weakness
  • Urine that smells bad
  • Blood in urine
  • Blocked flow of urine
  • Increased urge to urinate
  • Pain during urination
  • Pain that spreads to the lower abdomen and groin

What Do I Eat to Help Prevent Kidney Stones?

People who do not have a history of kidney stones do not need to make any changes in their diet. If you have had kidney stones before, these diet changes might help prevent future stones:

  • Reduce amount of salt and sodium in your diet. Too much salt increases calcium in urine.
  • Drink more water and fewer sodas.
  • Eat fewer foods that contain oxalate such as nuts, tea, coffee, dark green leafy vegetables, sweet potatoes, chocolate, wheat bran, and draft beer.
  • Reducing intake of animal proteins from meat, fish, pork, chicken, and eggs will reduce acid levels and help prevent uric acid stones.

Will Drinking Too Much Milk Cause Kidney Stones?

Many people believe that consuming too much dairy products will increase the risk for developing kidney stones. Studies have shown that eating three servings of dairy foods a day actually lowers your risk for having kidney stones.* Calcium in dairy seems to have a protective effect on health., although taking calcium alone in pill form will not reduce risk for kidney stones and might actually increase the risk for kidney stones.

See your doctor if you think you have a kidney stone. Your doctor will determine what kind of kidney stone you have and what medical or dietary treatment you may need.

For more information, visit The National Kidney Foundation or the National Institute of Diabetes and Digestive and Kidney Diseases.

Gary C. Curhan, MD, ScD; Walter C. Willett, MD, DrPH; Eric L. Knight, MD, MPH; Meir J. Stampfer, MD, DrPH. Dietary Factors and the Risk of Incident Kidney Stones in Younger Women: Nurses' Health Study II. Archives of Internal Medicine. 2004; 164:885-891.

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Page last updated: April 17, 2017