One of the nursing theories is Dorothea Orem's self-care theory, also called the self-care deficit theory. Nursing theories are important for several reasons. The profession is strengthened when knowledge is built on solid theories (Black, 2014). Theory is important for reasoning, thinking, making decisions, and supporting excellence in practice (Black, 2014). Dorothea Orem's theory is a conceptual model that provides a framework 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 related theories: self-care theory, self-care deficit theory, and nursing system theory (Black, 2014). The focus of Orem's model is the patient's ability to self-care. The process helps to design a specific nursing process for each patient that will provide for the patient's self-care deficit (Black, 2014). Self-care deficits exist when the patient has limitations and the need for self-care is greater than his or her abilities (Manzini & Simonetti, 2009). Orem's theory is based on self-care requirements, which are basic needs of individuals at all stages of life. life. A patient's ability or lack of ability to provide these self-care requirements for themselves determines the self-care deficit (Black, 2014). A patient's ability to take care of themselves depends on factors such as age, gender, current health status and sociocultural factors (Caetano & Pagliuca, 2006). The self-care deficit is then used to design a nursing plan that meets the patients' needs (Black, 2014). Self-care requirements can be divided into three categories...... half of the document ...... are HIV/AIDS patients: systematizing 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., & Guedes, M. (2012). The nursing process as a strategy in developing self-care skills. 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). Dorothea e. Orem, the nursing theory of self-care deficit. Retrieved from http://nursingtheories.weebly.com/dorothea-e-orem.html Application of Orem's Self-Care Deficit Theory. (2011). Retrieved from http://currentnursing.com/nursing_theory/application_self_care_deficit_theory.html