The appearance in 1940 of the second edition of Sir Thomas Lewis's "The Soldier's Heart and the Effort Syndrome"1 focused the attention of physicians once more on one of the most frequent causes of invalidism among soldiers. Because the symptoms resembled those of fatigue following effort in normal persons, Lewis suggested the name "effort syndrome." The name "neurocirculatory asthenia" was suggested by a team of medical reserve corps officers of the American Army2 sent to Colchester, England, to study the condition with Sir Thomas Lewis. They felt that the symptoms comprising effort syndrome in normal persons were not the same as those observed in neurocirculatory asthenia. Da Costa described its occurrence many years ago in the United States. He stressed that the condition was not confined to soldiers, since the symptoms were frequently present before enlistment. Fever, diarrhea, wounds, and strenuous existence of the soldiers were predisposing factors.