The intense physiological effect of consuming too much sugar or glucose, usually in the form of cakes, cookies and soda; eating excessive amounts of sugar makes the brain release dopamine and endorphins, often inducing a mild sense of euphoria and happiness. This is often accompanied by a strong surge of energy as the sugar hits the bloodstream.
Sugar highs often only last an hour or two, and as the level of glucose in the blood lowers it can often leave the subject feeling drained or unnaturally tired. If ingested with large amounts of caffeine, such as in the form of chocolate or cola, the subject can also become jittery, experience mild heart palpitations or suffer from temporary insomnia.
The term was made famous by the Movie "Empire Records", which starred "Coyote Shivers'" front man singing their infamous song: "Sugar High".
Jane Doe: Dude, sugar high's don't exist..