There are multiple reasons your adrenal system can become fatigued, and it is estimated that up to 80% of adults will developed a fatigued adrenal system in their lifetime.
What are your adrenal glands?
Your body has two adrenal glands, located just above each of your kidneys. As part of your endocrine system, your adrenal glands secrete more than 50 hormones, many of which are essential for life and include:
Glucocorticoids: These hormones, which include cortisol, help your body convert food into energy, normalize blood sugar, respond to stress and maintain your immune system's inflammatory response.
Mineralocorticoids: These hormones, which include aldosterone, help keep your blood pressure and blood volume normal by maintaining a proper balance of sodium, potassium and water in your body.
Adrenaline: This hormone increases your heart rate and controls blood flow to your muscles and brain, along with helping with the conversion of glycogen to glucose in your liver.
Together, these hormones and others produced by your adrenal glands control such body functions as maintaining metabolic processes, such as managing blood sugar levels and regulating inflammation; regulating your body's balance of salt and water; controlling your "fight or flight" response to stress; maintaining pregnancy; Initiating and controlling sexual maturation during childhood and puberty; producing sex steroids such as estrogen and testosterone.
Ironically, although your adrenal glands are there, in large part, to help you cope with stress, too much of it is actually what causes their function to break down.
In other words, one of your adrenal glands most important tasks is to get your body ready for the "fight or flight" stress response, which means increasing adrenaline and other hormones. As part of this response, your heart rate and blood pressure increase, your digestion slows, and your body becomes ready to face a potential threat or challenge.
While this response is necessary and good when it's needed, many of us are constantly faced with stressors (work, environmental toxins, not enough sleep, worry, relationship problems and more) and therefore are in this "fight or flight" mode for far too long -- much longer than was ever intended from a biological standpoint.