["American Journal of Human Biology, Volume 38, Issue 4, April 2026. ", "\nABSTRACT\nSystemic inflammation occurs when the immune system is chronically active due to repeated harmful exposures or dysregulation of the immune process. It is associated with the prevalence and poorer prognoses of many chronic diseases. Like many health indicators, its burden is often found to be greater in those of lower socioeconomic status. Little is known about how levels of systemic inflammation have changed over time in populations, nor how such changes may relate to socioeconomic status. This study uses data from National Health and Nutrition Examination Surveys (NHANES) to evaluate inflammation trends in the US population between the 1970s and 2010s. The results indicate a shift in structural immunity for the US adult population that corresponds with increasing systemic inflammation over time, with the trend being modestly stronger at lower income levels.\n"]