Stress is a whole-body experience and starts with your nervous system. When stress arises, your nervous system triggers an adrenal response to prepare your body to respond. In the short term, this benefits your survival, but over the long term, it can be detrimental to your health if your adrenal response is activated over a longer period. This article will take a closer look at the relationship between the autonomic nervous system and adrenal response, and the steps you can take to heal your adrenal response when it is depleted.
What Is The Autonomic Nervous System?
Your nervous system consists of two different parts: the somatic nervous system and the autonomic nervous system (ANS).
- The somatic nervous system is involved in the voluntary movements of your body, such as moving muscles.
- The autonomic nervous system, or ANS, is involved in involuntary functions, including managing your digestion, heart rate, and organ function.
The ANS also contains two different systems:
- The sympathetic nervous system (SNS) – activates a “fight or flight” response
- The parasympathetic nervous system (PNS) – activates the “rest and digest” response
How Does Your Autonomic Nervous System Affect Your Adrenal Response?
The relationship between your autonomic nervous system and adrenal response lies within the sympathetic and parasympathetic nervous systems.
The sympathetic response, known as the fight-or-flight response, will trigger an adrenal response. The parasympathetic response, also known as the rest-and-digest response, will essentially turn off the adrenal response.
Your adrenals are part of the NeuroEndoMetabolic (NEM) Stress Response System in your body. This system consists of six different circuits of related organs and systems that work to keep your body in balance. The different circuits are responsible for different bodily functions. These different circuits are:
- Hormonal
- Inflammation
- Neuroaffect
- Detoxification
- Bioenergetics
- Cardionomic
The Fight-or-Flight Response
When your body is in the fight-or-flight response, it takes two forms: a slow and a fast response.
Slow Fight or Flight Response
The slow response occurs through the HPA axis (hypothalamic-pituitary-adrenal). When this axis is activated, the hypothalamus releases cortisol-releasing hormone, which stimulates the pituitary gland to release adrenocorticotropic hormone. This hormone stimulates the adrenal cortex, the outer part of the adrenal gland, to secrete cortisol [1].
Fast Fight or Flight Response
The fast response is part of the Sympathoadrenal System (SAS). This system consists of your sympathetic nervous system and adrenal medulla, the inner part of your adrenal glands.
In the fast response, the adrenomedullary hormonal system (AHS) secretes hormones such as norepinephrine and epinephrine, also known as adrenaline, from the adrenal medulla. These hormones give your body an extra boost of energy as part of the fight-or-flight response.
Fight or Flight Symptoms and Hormones
This flood of norepinephrine and adrenaline activates various parts of the body, gearing them up to enable fleeing from threats. Symptoms include:
- A pounding heart
- Increase in blood pressure
- Rapid breathing
- Heightened senses
- Sweating
- A burst of energy
Adrenaline is a powerful hormone that affects many parts of the body. It is also stronger than norepinephrine.
Norepinephrine is a brain hormone that acts locally, affecting certain organs, like the brain, to keep you more alert. Norepinephrine also travels to the heart and causes the heart to beat more strongly. Without norepinephrine, for example, standing upright becomes a problem.
The balance between cortisol, norepinephrine, and adrenaline is critical for one to feel good, especially under stress.
The Rest-and-Digest Response
Once the stress clears, the parasympathetic response, the rest-and-digest response, is activated.
When this response is activated, the HPA axis is no longer activated, any leftover adrenaline is metabolized, and the body recovers from the effects of stress.
How Your Stress Hormones Flow
Your stress hormones work in a chain reaction. It starts with dopamine, which helps you feel motivated and focused. When dopamine is used up, it turns into norepinephrine, which helps you stay alert and awake. Norepinephrine can then be converted into epinephrine (adrenaline), the hormone that drives the “fight-or-flight” response when you’re under pressure.
When Norepinephrine Dominates
If your body produces too much norepinephrine, you stay in a state of constant alertness. You may feel tense, anxious, or “wired but tired.” This is called RSO (Reactive Sympathetic Overtone) — your body is stuck in “go mode.” You may not have the stronger adrenaline symptoms yet, but your system is running on high alert, which can affect sleep, focus, and emotional balance.
When It Escalates to Epinephrine
If stress continues, norepinephrine pushes into epinephrine, which is released by your adrenal glands. This can cause more intense symptoms such as a racing heart, palpitations, dizziness upon standing (POTS), or irregular heartbeats. This stage is known as RSR (Reactive Sympathetic Response) — your body is now in full overdrive. It becomes a positive feedback loop: the more adrenaline is released, the more your body stays on high alert, which leads to even more adrenaline production.
| Reactive Sympathetic Overtone (RSO) | Reactive Sympathetic Response (RSR) | |
|---|---|---|
| Severity | Less severe | More severe |
| Dominant Hormone | Norepinephrine | Epinephrine |
| Symptoms | • Tense • Anxious • Wired but tired • Sleep problems • Poor focus |
• High blood pressure • Anxiety • Muscle tremors • Dizziness on standing (POTS) • Insomnia • Headaches |
| Heart Involvement | • Heart pounding, but heart rate is regular | • Irregular heart rhythms • Racing heart • Palpitations • Tachycardia • Atrial fibrillation |
RSO and RSR are particularly problematic in stage three of a condition known as Adrenal Fatigue.
What Happens When Your Stress Persists?
When the stress continues, the AHS remains activated. The body is no longer able to effectively modulate the PNS to recover from the effects of stress. Additionally, the HPA axis remains activated, causing the adrenal glands to continuously produce cortisol.
This increases the demand on your adrenal glands, and eventually, your adrenal glands lose the capacity to secrete enough of these hormones to keep up with stress. This is the start of autonomic dysfunction. Imbalances within your NEM system will also start to arise.
These trigger the onset of Adrenal Fatigue, where your body is unable to keep up with long-term stress, resulting in various symptoms.
There are four different phases of Adrenal Fatigue. These are:
- Stage One: Alarm Reaction – the adrenal response is activated, and your body is in the fight-or-flight response. In this stage, your body is able to cope.
- Stage Two: Resistance Response – your adrenal glands start to struggle to keep up with the demand for cortisol, and circuits within the NEM system may start to become imbalanced, resulting in symptoms.
- Stage Three: Adrenal Exhaustion – there are four different sub-stages here: chronic single system dysfunction; multiple endrocrine axis dysfunction; disequilibrium state; and near failure. RSO and RSR can occur.
- Stage Four: Adrenal Failure – the adrenal glands are now exhausted.
The Adrenal Response in Stage Three Adrenal Fatigue
In stage three, your adrenal glands cannot keep up with the cortisol demand, and cortisol levels reduce. At this point, the body is in disarray, with only limited resources and adrenal response capacity available. It decides the best option is to run away from whatever is stressing it. This leads to the SAS to ramp up its activity with the AHS continuing to secrete adrenaline and norepinephrine, to prepare the body to flee.
Unfortunately, adrenaline is a hormone that has no opposing hormones to neutralize it. It triggers more adrenaline to be released, and thus, a positive feedback loop is created. This can eventually lead to a downward cascade of instability that, if not stopped, will end in collapse.
Oftentimes, RSR and RSO are intermingled with each other here. Both are present excessively with unrelenting stress. A multitude of sometimes sub-clinical symptoms begin. Some of these include:
- Lightheadedness
- Dizziness
- Changes in blood pressure
- Irregular heart rate
- Temperature intolerance
- Sweating
- Panic attack
- Postural orthostatic tachycardia- a faster heart rate when you stand up
- Fainting.
The RSO, RSR, and Adrenal Fatigue
When RSR and RSO occur, it’s important to consider all the symptoms as a whole picture rather than focusing on one aspect. The NEM stress response system can help to focus on the bigger picture.
In phase three of Adrenal Fatigue, the body becomes sensitized to nearly any stimulus that could become a stressor. An event that normally would have been shrugged off can start the cascade of bodily responses that will lead the person back into the swamp of extraordinarily high levels of adrenaline and norepinephrine, bringing on the flood of symptoms described above.
This flood could be triggered by simple activities, including:
- Having a disagreement
- Watching an action movie
- Doing high-intensity exercises
With the activation of the RSR, the body’s usually precise balance is compromised because the SAS directs more blood to the brain in order to ensure the survival of the body. This can lead to swings in the metabolic and hormone systems.
This leads to acute adrenal weakness and is known as an adrenal crash. The symptoms typically seen in Adrenal Fatigue become exaggerated under these conditions. Time for recovery from this kind of crash may be significantly longer, depending on the degree of weakness of the adrenals.
The “Slow Is Fast” Principle of Recovery
Recovery happens when you allow your body to slow down and reset. Grounding techniques, controlled breathing, and nourishing foods can help your nervous system calm and return to balance. Over time, chronic overstimulation can deplete dopamine, leading to fatigue and low motivation. By giving your body space to recover gradually, you support a return to steady energy and emotional stability.
Recovering from Adrenal Fatigue
In addition to calming and reducing overstimulation, finding the root cause of your stress is an important step in recovering from Adrenal Fatigue. While you may not be able to control all potential stressors in your life, there are some you can control.
Nutrition
Poor nutrition can increase inflammation in your body and increase the load of stress on your body. Some simple tips that you can follow to help manage stress nutritionally include:
Reduce foods high in added sugars and saturated fats- Choose unrefined carbohydrates rather than refined carbohydrates
- Have fruits and vegetables daily
- Drink water daily
- Reduce your caffeine intake
- Reduce your alcohol intake
Several nutrients and natural compounds may help to support basic adrenal functions and also act as antioxidants. Antioxidants help to neutralize unstable molecules, also called free radicals. These free radicals are produced in response to stress and can increase inflammation.
Some nutrients and natural compounds that act as antioxidants or that may help your adrenal response are [2]:
- Vitamin C
- Vitamin B5
- Magnesium
- Coenzyme Q10
- Carotenoids
- Polyphenols
- Probiotics
These nutrients and natural compounds can be found naturally in food. Some eating principles that will help you ensure you receive enough of these nutrients and compounds are:
- Choose unrefined carbohydrates over refined carbohydrates
- Eat fruits and vegetables daily
- Choose lean protein
- Add fermented products such as:
- Yogurt
- Kombucha
- Kefir
- Kimchi
- Miso
Exercise
A lack of exercise can place stress on your body; however, on the other end of the spectrum, if you are experiencing Adrenal Fatigue, too much exercise or high-intensity exercise can increase stress on your body.
If you are currently experiencing Adrenal Fatigue, focus on gentle exercises. These include gentle walking, restorative yoga, and stretching.
Managing Stress
While you may not be able to control certain stressors, such as stress from work, you can manage your stress levels through:
- Breathing exercises such as box breathing and single nostril breathing
- Practicing mindfulness
- Meditation
- Journalling
- Talking to someone about your stress, such as a friend, support group, or healthcare professional
Supplementation
Supplementation can help to support your adrenal response and reduce stress. However, supplementation should not replace a healthy diet.
If you are concerned that you are not receiving specific nutrients or natural compounds such as probiotics through your diet, you can receive them through supplementation. It may also help you to receive these nutrients in higher doses, which may be more beneficial.
Before taking supplements, always chat with your healthcare provider first. Some herbs, such as ashwagandha, can be too stimulating when your body is in a state of stress.
Closing Thoughts
While the adrenal response can be beneficial for your body, when stress is excessive, this adrenal response can be detrimental.
Simple steps, such as managing your stressors and ensuring you are eating a healthy diet, can help your body recover. However, it is also important to work closely with a healthcare provider who is trained in Adrenal Fatigue.
If you are looking for providers that understand adrenal health, we at Lam Clinic can help. We believe in Rooted Care that transforms lives and empowers futures. Book your first consultation and take a step towards adrenal recovery today!