The role of symptom perceptions and utilization of health promoting practices in illness behavior were explored across the adult lifespan. The first study (N = 396) assessed the health practices and perceptions about illnesses in well adults (ages 20 to 89) as well as perceptions about symptoms associated with a group of six specific illnesses. The second community study (N = 614) examined how symptom qualities (symptom severity, duration, and illness label) affect attributions of symptoms to aging and coping strategies in response to the symptoms. The findings revealed that while the elderly report more frequent performance of health promoting activities, perceptions about illnesses and how to prevent them are comparable across adulthood. Symptoms used to identify illnesses are also equivalent across adulthood (and aging) except for the reduced usage of mild ambiguous symptoms in identifying illnesses by the elderly. The frequency with which mild, short-term symptoms are attributed to aging increases with age of the subjects and leads to greater acceptance of the illness symptoms and more passive coping strategies. Clinical implications and policy recommendations are discussed.