Fig. 1
From: Transitioning from acute to chronic pain: a simulation study of trajectories of low back pain
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12967-019-2030-0/MediaObjects/12967_2019_2030_Fig1_HTML.png)
A Diagram of Hypothalamic–Pituitary–Adrenal (HPA) axis. In response to stress, the hypothalamus releases CRH, which activates the pituitary which secretes ACTH. ACTH stimulates the adrenal to secrete glucocorticoid. Glucocorticoid performs a negative feedback on the secretion of CRH and ACTH