Peripheral artery disease (PAD) is a progressive atherosclerotic occlusive disease affecting more than 8 million Americans, a number expected to rise sharply due to an aging population. PAD causes insufficient blood flow to the legs, which leads to debilitating, activity-induced, ischemic pain (i.e. claudication). Although health care providers consider claudication the hallmark symptom of PAD, it is reported by less than 29% of PAD patients. When individuals report symptoms inconsistent with classic claudication, provider suspicion of disease presence is not triggered; therefore patients do not receive the necessary diagnostic testing and subsequent diagnosis. The breadth of PAD symptom experiences based on age and gender is poorly understood, but is a crucial component to providing timely diagnosis and treatment in an attempt to prevent amputation, heart attack, stroke, and death. Consistent with the scientific mission of the National Institute of Nursing Research to expand nursing science by integrating the biological and behavioral sciences, the proposed study utilizes a mixed methods approach to provide an integrated, comprehensive, and biobehavioral understanding of the PAD symptom experience. Subjective data will be obtained through in-depth interviews and symptom reports during treadmill walking. Objective, physiologic data related to ischemic changes in calf skeletal muscle will be obtained during treadmill walking. The objectives of the proposed descriptive, exploratory, cross-sectional study are to elicit a comprehensive description of PAD symptoms and related physiologic data, and to determine the degree of correspondence to delineate causative mechanisms underlying symptoms (an NINR area of emphasis). This study will provide a comprehensive and accurate description of the subjective PAD symptom experience and will, for the first time, simultaneously evaluate subjective symptoms and objective physiologic ischemic changes in working skeletal muscles. This study has significant implications for the improvement of PAD assessment and diagnosis to optimize health by broadening currently accepted symptom descriptors, and to reduce health disparities by identifying age and gender differences in PAD symptom experiences. This study is foundational for future research to determine patterns of ischemia, their relationship to symptom report, and potential changes with therapeutic interventions, leading to the long term goal of developing and refining gender and age specific screening tools. The knowledge gained from this study has significant public health implications for the over 8 million undertreated, debilitated, and at-risk Americans that suffer daily from this painful, deadly, and life limiting disease--improving detection, diagnosis, and treatment.