The hormones cortisol and adrenalin are stored in the adrenal glands and released into the bloodstream when activated by stress. Together, they stimulate the fight or flight response. The evolutionary perspective suggests that during our 2.5 million formative years in the Paleolithic, acute rather than chronic stress was the norm and we evolved to handle stressful situations that resolved quickly.
A typical historical scenario might have been the sudden confrontation with a predatory animal. In response to such acute stress, the HPA axis of communication between the hypothalamus, the anterior pituitary gland and the adrenal glands engages. Cortisol and adrenalin are released into the bloodstream to increase breathing, heart rate, blood pressure and blood sugar levels while simultaneously redirecting all available energy away from nonessential activities towards those required for survival. Fuel including glucose, fatty acids, amino acids and ketones are directed away from digestion, growth, reproduction, and immunity and towards the brain and muscles for increased alertness, speed and strength. Once the acutely stressful event is over, stress hormones retreat and metabolic systems return to baseline.
What is Adrenal Fatigue?
Of course we face acute stress from time to time in our modern lives but we face a greater threat from chronic sub-acute stress that over-stimulates the adrenal glands and results in chronically elevated hormone levels. Eventually, although the adrenals continue to function, stress hormone output declines and cannot meet demand, creating a condition referred to as adrenal fatigue. During adrenal fatigue, metabolic systems that depend on stress hormone activation such as blood sugar homeostasis, are compromised.
In healthy, non-stressed individuals, when blood sugar dips too low during the day or even during sleep, cortisol activates and initiates processes that return levels to baseline. Without adequate cortisol, hypoglycemia results and symptoms of adrenal fatigue are felt. Hypoglycemia, in addition to sub-acute stressors such as not getting enough sleep night after night, sitting in traffic day after day, deadlines at work, the responsibilities of child care, financial worries, poor nutritional choices, too much caffeine, too much exercise, and more intense stressors such as a move, the death of a loved one, illness, the loss of a job or divorce, all contribute to activation of the HPA-axis and the stress response. A vicious cycle ensues where stress creates the need for increased glucose; a need which cannot be met by inadequate stress hormone production; which contributes to hypoglycemia; which creates stress, and so on and so on. Though a single bout of acute stress can over-stimulate the adrenals, more often than not, it’s the unprecedented levels of chronic mental, physical and emotional stress present in contemporary life that leads to adrenal fatigue.
What are the Symptoms of Adrenal Fatigue?
- Feeling exhausted for no apparent reason even in the morning after getting a normally adequate amount of sleep.
- Feeling exhausted and anxious at the same time.
- Feeling irritable and shaky or rundown and depressed.
- Having more energy in the evening.
- Trouble falling asleep or staying asleep through the night.
- Diminished ability to concentrate and remember things.
- Difficulty dealing with acute stress or recovering from illness.
- Craving salty and/or sweet calorie dense snacks.
- Increased abdominal fat.
Adrenal Fatigue is Reversible
It is extremely important to decrease sources of stress in order to bring stress hormone production back to normal levels. Getting adequate high quality sleep, avoiding excessive caffeine and alcohol as well as eating a nutrient rich diet such as the Paleo diet and taking care not to skip meals can do wonders for your wellbeing. You can read more on how to support your adrenals with proper lifestyle and nutrition in a companion article titled: Paleo & Adrenal Fatigue: How Primal Living Can Restore Your Energy.