The frequency and age distribution of linear enamel hypoplasia (LEH) in the dentition of 293 individuals from Latte Period sites (AD 800-1521) on Guam, Mariana Islands, are examined in this study. Individuals dying as subadults (before age 16) and as young adults (ages 16-21) have more frequent LEHs than those who survived to middle or late adulthood, documenting a relationship between LEH-causing stress events and reduced life expectancy. The age distributions of cribra orbitalia and skeletal infection in children who died by age 10 exhibit striking similarities to the etiological age patterns of LEH in children, and those with skeletal infection have more frequent hypoplasias than children without infection. The comorbidity of systemic stress and infection in children, and their impact on life expectancy, are interpreted in the biocultural context of high population density in the large coastal villages of the late prehistoric period in the Marianas.