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Understanding the HPA axis
While neurotransmitters help transmit signals along nerve pathways, other chemicals, called hormones, carry messages to organs or groups of cells throughout the body. Imbalances of certain hormones increase the risk for anxiety and may induce anxiety symptoms.
These hormones circulate in a pathway called the hypothalamic-pituitary-adrenal (HPA) axis, which influences mood. The hypothalamus is a part of the brain located above your brainstem, the pituitary gland sits below your brain, and the adrenal glands are located atop your kidneys. Together these bodies govern a multitude of hormonal activities in the body and may play a role in anxiety disorders. The autonomic nervous system, which triggers the fight-or-flight response and directs functions throughout the body, is responsible for the HPA axis
When you’re faced with a threat, the HPA axis allows you to respond quickly. However, in some people with anxiety disorders, this system remains in overdrive.
- 1. The hypothalamus secretes the hormone corticotropin-releasing factor (CRF) also called corticotropin-releasing hormone (CRH), which rouses the body.
- 2. CRF / CRH travels to the pituitary gland.
- 3. The pituitary gland secretes adrenocorticotropic hormone (ACTH).
- 4. ACTH circulates in the bloodstream, travelling to the adrenal gland.
- 5. The adrenal gland releases cortisol, another hormone.
- 6. Cortisol stimulates many reactions in your body, including a rush of energy and alertness.
The cortisol enables you to respond quickly to a threat. Normally, a feedback loop allows the body to disable these defenses when the threat passes. But in some cases, the floodgates never close properly, and cortisol levels rise too often or simply stay high.