A nursing health assessment is the systematic collection and analysis of a patient's physical, psychological, social, and spiritual data to understand their overall health, identify needs, and form the first step in creating a personalized nursing care plan. Nurses use interviews, observations, and physical exams (like head-to-toe assessments, vital signs, pain scales) to gather subjective (symptoms) and objective (signs) data, crucial for timely interventions, patient safety, and guiding effective treatment.