Which of the following symptoms is associated with an increased level of stress?

Chronic fatigue is a symptom often associated with increased stress levels. When an individual experiences high levels of stress over an extended period, it can lead to physical and mental exhaustion. This fatigue is not just typical tiredness; it often includes a sense of overwhelming weariness that can affect both daily functioning and overall quality of life.

In contrast, improved focus and heightened energy levels might initially be experienced by some individuals under stress, but these are typically short-term responses and can lead to burnout if stress continues. Similarly, increased productivity can occasionally be a temporary effect of stress, as certain individuals may become more driven to accomplish tasks under pressure. However, these effects do not reflect the long-term consequences of chronic stress, which most commonly manifest as chronic fatigue. Therefore, chronic fatigue is the most accurate symptom to associate with sustained increased levels of stress.