The incidence of people suffering from painful kidney stones is rising, sending more than half a million people to emergency rooms each year in the United States. A kidney stone is a hard object made from chemicals found in the urine. Usually these chemicals are eliminated by the kidneys, but sometimes they attach together and form stones that are difficult to pass normally, according to Kidney.org.

"Once a stone is large enough to be treated, it's been forming for as long as two years," says Marshall Stoller MD, an award-winning urologist who heads the University of California San Francisco's urinary stone division. "Many people think that having kidney stones is just bad luck. But there are many proven things you can control to keep your kidneys healthy."

The four tips that Stoller shares with Newsmax are also ways to keep your heart healthy, he says.

"Statistics show that people who have kidney stones also have an increased risk of having a cardiac event," he explains. "It has to do with body chemistry. Often, whatever is happening in the heart is also happening in the kidneys."

Here are his four steps to keeping both your kidneys and heart healthy:

1. Reduce your intake of salt to less than 2,300 milligrams daily.
2. Limit consumption of animal protein to a serving that's the size of the palm of your hand.
3. Drink adequate amounts of fluid so that you urinate often and your urine is clear, not bright yellow.
4. Get some form of daily exercise.

Stoller adds that adding a citrate solution and calcium to your daily diet can also help prevent stones.

"There is a misconception among the healthcare and lay communities that people who form calcium stones in their kidneys should avoid calcium," he says. "The opposite is true. If you have excess calcium in your urine, it may be coming from your bones. Replenishing your calcium supply supports overall health, especially your bones."

He says that in the 1990s, scientists found that drinking lemonade increased the citrate levels in the urine. But now, the research says it's not enough.

"Citrate solutions help prevent stone formation by reducing the ability of calcium in the urine to bind with oxalate, another common stone-forming chemical," he says. "To support daily kidney health, I recommend a citrate beverage such as Moonstone Kidney Health Beverage that contains the right amount of citrus salts, lemon juice, and vitamin B6 to optimize the body's chemistry."

Stoller encourages everyone to adopt a kidney- and heart-healthy lifestyle.

"Kidney stones are happening to people at an earlier age these days," he says. "And the earlier you develop a stone, the more likely you are to have chronic kidney disease later in life."