Which theory helps the nurse understand the ability of living things to adjust or adapt to continuous internal and external stimuli?

• A. Adaptation Theory
• B. Developmental Theory
• C. Growth Theory
• D. Systems Theory

Answer: (A)

Adaptation Theory describes how living beings continuously adjust to ongoing internal and external stimuli to maintain balance and function. In nursing, this explains why a person responds to illness, stress, or environmental changes with physiological and psychological adjustments aimed at preserving homeostasis. For example, the body may alter heart rate, breathing, or coping strategies in response to stress or new health conditions. This focus on tuning responses to constant stimuli is what sets Adaptation Theory apart from Developmental Theory (which maps stages of growth), Growth Theory (which emphasizes increases in size), or Systems Theory (which examines interrelated parts of a whole).