Activity intolerance is a frequent symptom in cardiopulmonary diseases or chronic illnesses that can interfere with a patient's activities in daily life and abilities of self-care. We should lay emphasis on this problem of potentiality or presence. The article determines the defining attributes, provides examples, identifies antecedents and consequences and demonstrates empirical references through the procedures of concept analysis. Finally, awareness of nursing staffs and development of nursing interventions are essential in the care of activity intolerance patients.