Answer:
Adrenal fatigue is a term used in functional medicine to describe a syndrome of chronic stress. When we experience stress, the hypothalamus in the brain activates a series of changes that lead to, among other things, the production of cortisol from the adrenal glands (located on the top of the kidneys). When the stress dissipates, a feedback mechanism sends messages to the brain to turn off the stress response, and the body returns to balance.
In our modern hectic world, however, many of us experience chronic unremitting stress, leading to chronic activation of the adrenal glands with increased production of cortisol. We can measure this in the blood, saliva, and urine - there is a higher daily output of cortisol. This is aggravated if our stress includes feelings of shame or social isolation, or if we are sleep-deprived, eating a poor diet, or leading a sedentary life. Eventually, the adrenal glands may not be able to keep up with this demand, and the normal cortisol response becomes dysregulated; the physical effects of this can lead to persistent fatigue, often known as adrenal fatigue. Chronic stress also suppresses the immune system and may increase the likelihood of inflammation, infections, depression, premature aging, cardiovascular disease, autoimmune disease, and even cancer.
The good news is that there are many things that we can do to reverse this trend. Mind-body therapies like meditation and guided imagery can help to reduce our perception of stress, calm the immune system, reduce inflammation, and spare the adrenal glands. Finding meaning in difficult circumstances can also motivate us to re-frame our stories and to rearrange our priorities and lead a more authentic life, which has also been shown to lower stress. Diary writing, gratitude, and self-disclosure are also beneficial, as are tai chi, Qi gong, massage, and yoga. Cultivating "transcendent" positive emotions such as the awe that we might feel out in nature or listening to a beautiful piece of music has also been shown to lower stress as well as markers of inflammation. The key thing here is to engage in these practices on a regular basis so that you regularly turn off your stress response and give your adrenal glands the "rest" that they are intended to have on a daily basis.
Many integrative practitioners will also prescribe adaptogenic herbs that may help us to "adapt" to stress and to reduce activation of the adrenal glands; these include botanicals like ginseng and ashwagandha. These are meant to be used on a short-term basis (no more than three to six months). And of course, be sure to get plenty of sleep and rest, move your body every day, and eat a plant-based diet rich in fruits, vegetables, fiber, seafoods/fish, and fermented foods to help keep your gut, your brain, and your immune system healthy.