Definition: The hypothalamic-pituitary-adrenal axis is a complex set of interactions between the hypothalamus (a part of the brain), the pituitary gland (also part of the brain) and the adrenal or suprarenal glands (at the top of each kidney.) The HPA axis helps regulate things such as your temperature, digestion, immune system, mood, sexuality and energy usage. It's also a major part of the system that controls your reaction to stress, trauma and injury.
Research links fibromyalgia and chronic fatigue syndrome with abnormalities in genes involved in the HPA axis. (Primarily the hypothalamus in fibromyalgia and primarily the adrenals in chronic fatigue syndrome.)
The HPA axis also is involved in anxiety disorder, bipolar disorder, post-traumatic stress disorder, clinical depression, burnout and irritable bowel syndrome.
Also Known As: hypothalamic-pituitary-adrenal axis