THE THEORY of Unpleasant Symptoms (TOUS) was developed to enhance understanding of relationships among multiple symptoms and symptom experiences to manage unpleasant symptoms through effective interventions.1,2 Although the TOUS has been used to guide studies in many areas of nursing,3-7 no formal critique of the theory has been published since 2000.8 Therefore, using Fawcett and DeSanto-Madeya’s9 framework for analysis and evaluation of nursing theories,weconductedacomprehensivecritical analysis and evaluation of the TOUS.