Figure 1.

Interactions between sensory neurons, immune system, and endocrine system to produce pain in a sex-biased manner. External and internal noxious stimuli are detected by sensory neurons, which communicate to the immune and endocrine systems to modulate pain outcomes. Interactions between these systems are further affected by changes in cellular metabolism. Chronic pain disorders are more commonly diagnosed in women. Furthermore, women are disproportionately affected by chronic pain disorders, such as fibromyalgia and migraine, suggesting female-biased mechanisms in pain signaling and communication between the nervous, immune, and endocrine systems.