What is the Origin of HPA Axis Overdrive?

The term combines the anatomical components—Hypothalamus, Pituitary, Adrenal glands—with the concept of "overdrive," signifying excessive functional output. This axis is the neuroendocrine core of the stress response, governed by the release cascade: CRH from the hypothalamus, ACTH from the pituitary, and finally cortisol from the adrenals. The term clinically describes a hyperactive stress response phenotype.

What is the Mechanism of HPA Axis Overdrive?

Chronic stress stimuli maintain a high level of CRH and ACTH secretion, overriding the normal negative feedback mechanisms where high cortisol typically inhibits the hypothalamus and pituitary. This sustained signaling leads to adrenal hypertrophy and persistent hypercortisolemia. The constant high level of cortisol disrupts circadian rhythmicity, promotes gluconeogenesis, and shifts energy partitioning toward visceral fat storage, contributing to metabolic and psychological strain.

HPA Axis Overdrive ∞ Area

HPA Axis Overdrive

Meaning

A state of chronic, excessive activation of the Hypothalamic-Pituitary-Adrenal (HPA) axis, the body’s central stress response system, resulting in persistently elevated or dysregulated circulating levels of cortisol. This pathological condition is typically a response to chronic psychological or physiological stress, moving the system beyond its normal homeostatic range. Clinical manifestations often include sleep disruption, abdominal adiposity, and immune dysregulation.