Dr. John Milner of Loyola University Chicago Stritch School of Medicine, in Maywood, Ill., advises patients trying to ward off painful kidney stones to not reach for the iced tea.

"For many people, iced tea is potentially one of the worst things they can drink," Milner says in a statement. "For people who have a tendency to form kidney stones, it's definitely one of the worst things you can drink."

Kidney stones are crystals that form in the kidneys or ureters, the small tubes that drain the urine from the kidney to the bladder, Milner explains. The most common cause of kidney stones is the failure to drink enough fluids. Dehydration combined with increased iced tea consumption raises the risk of kidney stones in people prone to develop them.

"People are told that in the summertime they should drink more fluids," Milner says. "A lot of people choose to drink more iced tea, thinking it's a tastier alternative. However, in terms of kidney stones, they're getting it going and coming. They're actually doing themselves a disservice."

To remain hydrated there is no better alternative than water, Milner said.