As children grow older, they may undergo other screening tests. For example, children may undergo testing for tuberculosis, which is evaluated with a skin prick test called the PPD (purified protein derivative). Parents are asked to watch the pricked area for 48 to 72 hours to see if any redness, hardness or blistering appears. Children also may have their iron and lead levels tested through taking a sample of blood.

Some physicians may recommend that some lab tests be performed at regular intervals, such as a urine test to assess kidney function. In many cases, however, lab tests are performed on children only in circumstances where a physical examination or medical history indicates the possible presence of a disease. For example, a physician may recommend that a child or adolescent who is obese and has a family history of diabetes mellitus undergo a blood test to check the level of glucose (blood sugar).