SEATTLE -- Kidney stones are more common than you may realize. About two out of 10 people will get them.

"They're terribly painful," said Dr. John Swartzberg with the UC Berkeley Wellness Letter.

So you don't want them.

Swartzberg says much of the advice given to patients over the years, such as cut protein or avoid colas, is questionable. But, he says, there are things you can do that appear to be truly helpful.

"One of them is drinking plenty of fluids," he says. "There's fairly good evidence for that. There's also fair evidence for restricting the amount of sodium you take in. Aim for less than 2,400 mg a day."

Doctors used to tell people who had kidney stones to avoid calcium because most of these stones are made of calcium.

"And yet when it's looked at carefully, calcium at least from milk products seems to reduce the incidence of kidney stones. So today we don't tell people to avoid calcium, we tell them to make sure you get considerable amount of calcium from your diet."

Acidic drinks, such as lemonade or orange juice, might help, but excessive amounts of vitamin C can lead to kidney stones. So watch the supplements.

More Information:

kidney.org