Which of the following might indicate a need to assess for edema?

A sudden weight gain can indicate a need to assess for edema because it often suggests that the body is retaining excess fluid. Edema is a condition characterized by swelling caused by the accumulation of fluid in the tissues, which is often linked to factors such as heart failure, kidney issues, or inflammation. When a person's weight increases quickly and significantly, it can be a sign that they are experiencing fluid retention rather than changes in body fat or muscle mass.

Monitoring weight is crucial in healthcare settings, as sudden fluctuations can provide valuable insights into a patient's health status. While the other options may have important implications for a patient's overall health, they do not directly point to fluid retention as a sudden weight gain does. For instance, weight loss could indicate dehydration or poor nutritional intake, difficulty with mobility may relate to musculoskeletal issues, and increased energy levels generally suggest good health and wellness rather than fluid retention.