Self-rated health (SRH) and subjective life expectancy (SLE) are widely used for understanding health and predicting mortality. However, what these items measure remains unclear, due to the lack of conceptual frameworks. We administered a web survey across the United States, Great Britain, Germany, Spain, and Mexico. The questionnaire included SRH and SLE, each immediately followed by a question that probed respondents' thought processes. We examined the relationship between SRH and SLE, the response difficulty, and attributes that respondents considered for forming responses. Overall, SRH and SLE were moderately related, eliciting different information and varying in difficulty. Compared to SLE, SRH was perceived as easier but covered a narrower information spectrum. While illness and health behaviors were dominant attributes of SRH responses, family longevity history, life situations, and lack of control were additionally considered for SLE. When combined, SRH and SLE may capture a fuller range of attributes germane to health and mortality.