Which of the following factors is known to increase sensitivity to pain?

Chronic fatigue significantly increases sensitivity to pain due to several factors related to the body's physiological and psychological state. When an individual experiences chronic fatigue, it can lead to a heightened perception of pain, often referred to as hyperalgesia. This condition arises because persistent fatigue affects the central nervous system and can lower the body’s ability to manage stress and pain effectively.

Moreover, chronic fatigue can contribute to the release of pro-inflammatory cytokines, which play a crucial role in pain perception. In this state, the body might also experience disruptions in sleep patterns, leading to changes in hormone levels such as cortisol, which can further exacerbate the sensitivity to pain.

While frequent exercise, low blood sugar, and a healthy diet can influence overall health and well-being, they do not have the direct and consistent impact on pain sensitivity that chronic fatigue does. Frequent exercise typically has a beneficial effect on pain tolerance, while low blood sugar can lead to discomfort but isn't a direct correlate with increased pain sensitivity in the same context. A healthy diet is generally supportive of bodily functions and can promote overall wellness, but it does not have a direct relationship to increasing sensitivity to pain like chronic fatigue does.