“Fluid volume excess” is a common clinical nursing problem. Not only is it related to renal function impairment, it also affects overall systemic function if not monitored or treated in a timely manner. However, when should nursing diagnosis intervene? The question has always confused the clinic nurses. Although the diagnosis can be adopted, clear definition is lacking. Therefore, the purpose of this article is to explore the application of nursing diagnosis with focus on definition, differential diagnosis, theoretic background, and nursing process by literature review. The review article is intended to provide clinic nurses with the information to consider the nursing process and to provide professional and high quality care to patients with accuracy and confidence.