(NBC) - There's nothing better than iced tea to beat the heat. More than 128 million Americans drink it every day, adding to nearly 2 billion gallons consumed in a year. But indulging in iced tea could lead to a painful problem.
Shantay Oeloquin recently ended up in the emergency room with a kidney stone.
"It's more painful than child birth," she said.
She says in an effort to quit diet sodas she switched to iced tea. Her doctor, S. Alexis Gordon, a urologist at Texas' Baylor Grapevine, says iced tea may have been part of the kidney stone culprit.
"The run of the mill, restaurant brand tea tends to have the higher oxalate," Gordon explained. "Some of the black teas have higher amounts, but there are some who have fewer."
Oxalate is the key chemical that can lead to kidney stones, which affect about 10 percent of people.
Why just iced tea? Doctors say people drink more tea when it's on ice, compared to sipping hot tea.
The Tea Association of the USA responded by quoting a Harvard study that found the opposite. That study followed 81,093 women for eight years and found for each eight ounce cup of tea consumed daily, the kidney stone risk appeared to lower by 8 percent.
Gordon says it's about the amount and the kind you drink. Green and chamomile teas have lower oxalate levels.
"As long as you enjoy your iced tea but you make up for it with water, it's all about dissolving of minerals," she said.
Shantay is done with the Southern staple. Spinach and chocolate, also high in oxalate, are off her menu as well.
"That's what's causing my stones," she said. "I can absolutely go without it for the rest of my life."
Doctors say lemons, often served with iced tea, are high in citrates and can ward off kidney stones.