HPA axis and your stress hormones
The HPA-axis (hypothalamic-pituitary-adrenal axis) is simply the connection between your hypothalamus, pituitary and adrenal glands—and it’s an important part of the cascade that’s signaled when your brain senses fear. The HPA-axis effectively governs how you respond to a perceived stressor by releasing hormones that help regulate the body. When your HPA-axis is functioning properly, you’re effectively able to manage stress and return back to your baseline. But if it’s over or under-stimulated from consistent stress exposure, it can become dysregulated and make it difficult for you to cope with everyday stressors that never used to phase you.
Cortisol is your chief stress hormone that’s produced by your adrenal glands and regulated by the HPA-axis. It plays a crucial role in your fight-or-flight response, but it also has other important functions like maintaining your blood sugar levels, regulating your metabolism and supporting the immune system. In a healthy stress response, cortisol rises to help your body make use of its energy reserves, then returns to its normal levels once the perceived threat has passed.
If you’re under constant, prolonged stress, instead of lowering after the stress has passed—cortisol can remain high. Long term exposure to elevated levels of cortisol can negatively impact how you feel each day—from your mood and energy levels to your sleep, how your sex hormone's function and how your body utilizes energy.