In order to clarify the cause of sudden unexpected death (SUD) in the youth and to design new methods for the prediction or prevention of SUD, 9 cases of Okinawan subjects, aged 15 to 29 (mean 22.1 years old), were investigated by autopsy and preventive study. All the subjects died within one hour of symptom onset in the period from April, 1982 to January 1991 in Okinawa prefecture and were examined as medico-legal autopsies in the University of the Ryukyus. The main results were as follows: 1. Eight out of 9 cases were male including 2 obese subjects. Although there were past histories of ?gCoarctation" and "Schizophrenia", in two cases, but including these, all cases were asymptomatic and apparently healthy. 2. According to the causes of SUD suspected by the pathological studies, there was: ischemic heart disease in 2 cases; acute myocardial infarction, bridge formation of a branch of the coronary arteries, hypertrophic cardiomyopathy in 1 case; rupture of the aorta in 1 case; parchment-like ventricle in the 1 female case; no other significant organic abnormalities were recognized in the other 4 cases, including 3 cases who were diagnosed as "Sudden Manhood Death Syndrome". 3. In order to predict and prevent sudden deaths in the youth, it is not enough adding further medical examinations or improving the health examination program in school. It may also be indispensable that we should make every efforts to build up horizontal and vertical health administrative systems for private health check information between schools, and among communities and workshops.
