The National Heart Lung and Blood Institute and the American Academy of Pediatrics recommend routine cholesterol screening of children between the ages of 9 and 11 and again between 17 and 21.  The guidelines have been in place since 2011, but many parents still wonder if they're necessary.

Cleveland Clinic Cardiologist Dr. Michael Rocco says the screening is designed to detect risk factors for atherosclerosis, or a build-up of plaque in the arteries.

"Early identification of people at-risk is important because atherosclerosis, buildup of plaque in arteries, is a process that begins early and progresses through life," said Rocco.

The guidelines include a lipid screen, which calculates total cholesterol, including high-density lipoprotein or "good" cholesterol, low-density lipoprotein or "bad" cholesterol, and triglycerides. Elevated triglycerides and LDL raise the risk of later cardiovascular disease.

In the past, children were tested only if there were red flags such as obesity, diabetes or a family history of heart disease.  But as many as 60% of these cases were being missed.

Rocco says the point of identifying children who may be at-risk is not to put them on medication. He says it's to educate them and their parents about lifestyle changes, like a healthier diet and exercise, to get them off the road to atherosclerosis.

"These guidelines are not there to identify people specifically for treatment but to identify children that may be at risk so that the appropriate management can be instituted," Rocco said.

The National Heart, Lung, and Blood Institute considers an acceptable non-HDL result for children and adolescents, which is found by subtracting your HDL cholesterol from your total cholesterol, to be below 120. Triglycerides should be below 140.