The child in the question has all of the classic symptoms of childhood pheochromocytoma. In adults, the episodes of hypertension are more paroxysmal than in children, where the hypertension is more sustained. While it is an unusual diagnosis in children, pheochromocytoma must be considered in the evaluation of a patient with hypertension who has intermittent symptoms described. Pheochromocytoma can be associated with tuberous sclerosis, Sturge-Weber syndrome, ataxia-telangiectasia, and it can be inherited as an autosomal dominant trait.All of the other answers are possibilities in an adolescent-age child, but the concurrent finding of hypertension suggests an alternative diagnosis. Pregnancy would be unusual because of her age, but the diagnosis must be considered for practically all complaints in an adolescent of childbearing age. Brain tumors or migraine headache would be unlikely to produce the cardiac finding of "racing heart" reported in this child. Diabetes can produce a variety of findings, but important clues missing from this case include frequency of urination, weight loss, and other classically seen symptoms. Adolescent fainting spells (vasovagal reaction) are common, and many of the symptoms reported can occur during an episode. They commonly are seen during stressful situations, in groups of adolescents, or sometimes with minor symptoms; hypertension is not one of the features.