One of the nursing theories is Dorothea Orem's Self-Care Theory, also called Self-Care Deficit Theory. Nursing theories are important for several reasons. The profession is strengthened when knowledge is based on solid theory (Black, 2014). Theory is important for reasoning, reflection, decision-making and to support excellence in practice (Black, 2014). Dorothea Orem’s theory is a conceptual model that provides a structure for critical thinking in the nursing process (Black, 2014). A conceptual model provides a comprehensive and holistic perspective of nursing (Black, 2014). Orem published his theory in 1959 and continued to develop his model, eventually formalizing three interrelated theories: self-care theory, self-care deficit theory, and nursing system theory (Black, 2014). The Orem model focuses on the patient's ability to care for themselves. The process helps design a nursing process specific to each patient that will address the patient's self-care deficit (Black, 2014). Self-care deficits exist when the patient has limitations and self-care needs exceed their capabilities (Manzini & Simonetti, 2009). Orem's theory is based on self-care requirements, which are basic needs of individuals at all stages of their lives. life. A patient's ability or inability to provide this self-care determines the self-care deficit (Black, 2014). A patient's ability to care for themselves depends on factors such as age, gender, current health status, and sociocultural factors (Caetano and Pagliuca, 2006). The self-care deficit is then used to design a nursing care plan that meets the patients' needs (Black, 2014). Self-care needs can be divided into three categories...... middle of article ......are and HIV/AIDS patients: systematization of nursing care.Revisto Latino-Americana Enfermagen , 14(3), 336-345. Retrieved from http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-11692006000300006 Sampaio, C. and Guedes, M. (2012). The nursing process as a strategy for developing skills for self-care. Acta Paulista de Enfermagen, 25(spe2), 96-103. Retrieved from http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-21002012000900015Black, B. (2014). Professional nursing: concepts and challenges. (7 ed., pp. 266-282). St. Louis, MO: Elsevier. Gonzalo, A. (2011). Dorothée e. Orem nursing theory of self-care deficit. Retrieved from http://nursingtheories.weebly.com/dorothea-e-orem.html Applying Orem's Self-Care Deficit Theory. (2011). Retrieved from http://currentnursing.com/nursing_theory/application_self_care_deficit_theory.html