How fast or slow does the process of dysregulating the stress response system go before a disease emerges? This chapter builds a model for how this process works over the lifespan. The apparently sudden onset of diabetes or heart disease in our fifties or sixties can often be traced to dysregulations that began years or decades before, invisible to the unsuspecting and asymptomatic. Toxic stress accelerates illness and speeds up aging. How do we know if we’re on a fast track to future illness and early death? And when is the best time to intervene? That depends on how we measure stress. Consider Teresa Langford’s pathways from genes to stress to illness over 53 years.