A 10 year old with a dark neck is not necessarily hyperinsulinemic. Although a patient with hyperinsulinemia may present with a manifestation of acanthosis nigricans, a darkening of the skin on the neck, this does not allow the doctor to make a direct diagnosis of hyperinsulinemia. A history of relevant disease, medication history, physical examination and testing of blood glucose and insulin levels are also required to determine the presence of hyperinsulinemia.