The examination of medical students at the end of their course of studies offers an opportunity to investigate physiological changes occurring in an emotionally stressful situation in healthy persons. Under such and similar circumstances eosinopenia1-4and accelerated coagulation5,6have been demonstrated. On close study of the life histories of a number of patients with coronary occlusion it has been found that mounting emotional stress frequently preceded such an event7,8; it was in a number of instances complicated by an acute additional stressful experience close to the occurrence of cardiac infarction. The similarity of this sequence of events with the situation of preexamination tension terminating in the stress of the examination itself prompted us to study the level of blood cholesterol and its fractions bound to α- and β-lipoprotein under these circumstances. Since a number of patients with coronary artery disease exhibit hyperuricemia, and since stress and corticotropin