Whipples triad is a set of three conditions that need to be met in order to accurately characterize a hypoglycemic episode.The three conditions are the following:

The signs and symptoms of hypoglycemia are present (see section below on Signs and Symptoms)
A low blood glucose measurement is present, typically less than 70 mg/dL (3.9 mmol/L)
The signs and symptoms of hypoglycemia resolve after blood glucose levels have returned to normal

Age
The biggest difference in blood glucose levels between the adult and pediatric population occurs in newborns during the first 48 hours of life. After the first 48 hours of life, the Pediatric Endocrine Society cites that there is little difference in blood glucose level and the use of glucose between adults and children. During the 48 hour neonatal period, the neonate adjusts glucagon and epinephrine levels following birth, which may cause temporary hypoglycemia. As a result, there has been difficulty in developing guidelines on interpretation and treatment of low blood glucose in neonates aged less than 48 hours. Following a data review, the Pediatric Endocrine Society concluded that neonates aged less than 48 hours begin to respond to hypoglycemia at serum glucose levels of 55–65 mg/dL (3.0-3.6 mmol/L). This is contrasted by the value in adults, children, and older infants, which is approximately 80–85 mg/dL (4.4-4.7 mmol/L).In children who are aged greater than 48 hours, serum glucose on average ranges from 70 to 100 mg/dL (3.9-5.5 mmol/L), similar to adults. Whipples triad is used to identify hypoglycemia in children who can communicate their symptoms.
Addisons disease is associated with chronically low levels of the stress hormone cortisol, which leads to decreased glucose production.Hypopituitarism, leading to decreased growth hormone, is another cause of hypoglycemia in children, particularly with long periods of fasting or increased exercise. Inborn errors of metabolism
Briefly, inborn errors of metabolism are a group rare of genetic disorders that are associated with the improper breakdown or storage of proteins, carbohydrates, or fatty acids. Inborn errors of metabolism may cause infant hypoglycemia, and much less commonly adult hypoglycemia. Disorders that are related to the breakdown of glycogen, called glycogen storage diseases, may cause hypoglycemia. Normally, breakdown of glycogen leads to increased glucose levels, particularly in a fasting state. In glycogen storage diseases however, glycogen cannot be properly broken-down, leading to inappropriately decreased glucose levels in a fasting state, and thus hypoglycemia. The glycogen storage diseases associated with hypoglycemia include type 0, type I, type III, and type IV, as well as Fanconi syndrome. Insulinomas
A primary B-cell tumor, such as an insulinoma, is associated with hypoglycemia. This is a tumor located in the pancreas. An insulinoma produces insulin, which in turn decreases glucose levels, causing hypoglycemia. Normal regulatory mechanisms are not in place, which prevent insulin levels from falling during states of low blood glucose. During an episode of hypoglycemia, plasma insulin, C-peptide, and proinsulin will be inappropriately high. Non-B cell tumors
Hypoglycemia may occur in people with non-B cell tumors such as hepatomas, adrenocorticoid carcinomas, and carcinoid tumors.