Middle-aged individuals were once considered to have the highest risk for kidney stones, but the findings of a new study revealed that this has changed. Researchers have observed that the occurrence of the condition has increased among U.S. teens particularly girls who are African-Americans.

According to pediatric urologist Gregory Tasian from The Children's Hospital of Philadelphia, the emergence of kidney stones in young people raises concern since there is limited information on the best treatment for children who have the condition.

"The fact that stones were once rare and are now increasingly common could contribute to the inappropriate use of diagnostic tests such as CT scans for children with kidney stones," Tasian said. "Health care providers historically have not been accustomed to evaluating and treating children with kidney stones."

Common symptoms of the condition, also known as nephrolithiasis, include abdominal pains and nausea, but there are instances when the symptoms become more severe. Problems could be worse with larger stones as these may not go through the urinary tract. Doctors may have to resort to more invasive methods such as surgery to remove them.

Tasian said that he first observed the increased occurrence of kidney stone in kids when he started his practice in 2005.

He said that other urologists who have been practicing for decades noticed that early in their careers, the children with kidney stones are often those who have rare and inherited metabolic conditions. The kidney disease now affects relatively healthy children as well.

Tasian and colleagues, whose study was published in the Clinical Journal of the American Society of Nephrology on Thursday, said that poor water intake could be a likely reason for the increase in kidney stones among kids. Another factor could be poor dietary habits, usually involving an increased intake of sodium and decreased intake of calcium.

Dehydration that spurs growth of kidney stones is likewise linked to poor water intake and warmer temperatures. The researchers said that encouraging kids to drink more water may reduce their likelihood of developing the painful condition.

"If we can get adolescents to drink more water, we can very likely reduce the chance they are going to develop stones," Tasian said.

Photo: Beatrice Murch | Flickr