Final answer:
The main difference lies in defining characteristics which are present in an actual nursing diagnosis, but not in a risk nursing diagnosis. A risk nursing diagnosis is focused on prevention, while an actual nursing diagnosis addresses current signs and symptoms.
Step-by-step explanation:
The primary difference between a risk nursing diagnosis and an actual nursing diagnosis is that defining characteristics are not part of a risk diagnosis. An actual nursing diagnosis is based on evidenced signs and symptoms that are present, while a risk nursing diagnosis is about potential problems that could develop if nurses do not intervene. A risk nursing diagnosis does not include nursing interventions; instead, it identifies potential areas of concern so that preventive measures can be planned and implemented.