Dorothea Orem was an American nursing theorist best known for developing the Self-Care Deficit Nursing Theory. Born in 1914, she worked as a nurse and educator, focusing on the importance of patient self-care in promoting health and well-being. Her theory emphasizes that individuals can take responsibility for their own health, and nurses play a crucial role in supporting this process. Orem's work has significantly influenced nursing practice and education. Her theory is structured around three interrelated theories: self-care, self-care deficit, and nursing systems. These concepts guide nurses in assessing patient needs and designing effective care plans that empower patients to manage their health.