Evaluating adolescents with fatigue.

Although most adolescents who complain of fatigue do not have a serious medical illness, the complaint cannot be dismissed without further investigation. If the diagnosis remains uncertain after a careful history and a thorough physical examination, laboratory tests, including complete blood count, erythrocyte sedimentation rate, urinalysis and an Epstein-Barr antibody profile, may be considered next. If the etiology is still unclear, sequential visits often provide clues for the physician and reassurance for the family.