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The Autonomic Nervous System and Adrenal Response

All stress trigger an adrenal responseThe body has an adrenal response to severe stress from any source by activating the “fight or flight” system. The hormones responsible are norepinephrine and epinephrine (also called adrenaline).

When a stressor is recognized, the hypothalamic-pituitary-adrenal (HPA) axis is set in motion. At the end of this stream of hormones, the adrenal response is to release cortisol, fighting the effects of stress. The adrenomedullary hormonal system (AHS) may be activated if stress is severe. The adrenal medulla is instructed to put out adrenaline, giving the body an extra boost of energy as part of the fight or flight response.

Once the stress is reduced, the opposite system is activated. The AHS rests, and the HPA axis returns to normal function. This is the “rest and digest” response. This system is primarily regulated by the parasympathetic nervous system or PNS. With this system, the body relaxes, any leftover adrenaline is metabolized, and the body recovers from the effects of stress.

The Adrenal Response and Adrenal Fatigue

When the adrenal glands come under continuous bombardment from stressors, the demand for cortisol and other stress hormones becomes too great. The adrenals eventually lose the capacity to secrete enough of these hormones.

When the stress continues, as it so often does in our world, the AHS remains activated. The body is no longer able to effectively modulate the PNS to recover from the effects of stress.

This marks adrenal exhaustion, an advanced stage of a condition known as Adrenal Fatigue Syndrome (AFS). 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 AHS continuing to secrete epinephrine, or adrenaline, to prepare the body to flee.

Epinephrine is a powerful hormone that affects many parts of the body. Norepinephrine is a neurotransmitter 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 stronger. Some people report their heart pounding harder than normal symptomatically. Both of these substances activate various parts of the body, gearing them up to enable fleeing from threats. Adrenaline is much stronger than norepinephrine. Some of each is required for daily living. 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.

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.

The Reactive Sympathoadrenal Response (RSR)

With the body in phase 3 of adrenal fatigue and stress continuing, the sympathoadrenal system (SAS) ramps up its activity. The SAS is responsible for activating and inactivating the adrenal glands, and releasing both norepinephrine and adrenaline.

This brings on an automatic series of body responses, called the Reactive Sympathoadrenal Response (RSR), that flood the body with adrenaline. In contrast, the Reactive Sympathetic Overtone (RSO), also known as adrenaline dominance, refers to an overload of norepinephrine. There are significant differences. RSO is a bit less intense than RSR. Heart pounding may be felt with RSO, but heart rate is regular. RSR, on the other hand, can trigger tachycardia, PVCs, and atrial fibrillation when excessive.

Your doctor may not be able to explain adrenal response symptomsOften times RSR and RSO are intermingled with each other. Both are present excessively with unrelenting stress. A multitude of sometimes sub-clinical symptoms begin. These may include responses from the adrenals, a lightheaded feeling, variable blood pressure, irregular heart rate, cold and heat intolerance, dizziness, sweating, panic attack, postural orthostatic tachycardia, and fainting. Excessive amounts of adrenaline and norepinephrine cause some of these symptoms. Others can be brought on by an imbalance of the two chemicals.

This phase represents a stage of adrenal fatigue where careful examination over a period of time is required to accurately evaluate the condition. Many physicians only see a ‘snapshot’ of a patient’s symptoms, missing the root cause. The focus first is placed on the heart, as irregular heart rate is often the first clinical complaint that brings the sufferer to their physician. Cardiac workup is invariably normal, and patients are told to go home and “relax”. Due to the sometimes vague nature of AFS symptoms, some physicians don’t consider all of them. What is needed is more of a ‘video’ than a ‘snapshot’, covering the patient’s symptoms across time.

The RSR and Adrenal Fatigue

Conventionally trained physicians typically are presented a narrow picture of the constellation of adrenal response symptoms, only addressing one symptom or one organ system that appears to be most affected. A more comprehensive viewpoint is necessary. This needs to take into consideration all of the systems of the body and the way they are interrelated.

This viewpoint is called the NeuroEndoMetabolic (NEM) Stress Response model. Using the NEM model, healthcare practitioners consider the entire symptom picture, including several visits over time. Patience is called for.

Especially in phase 3 of AFS, when RSR is happening, 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 activities as simple and ordinary as eating a large meal full of carbohydrates, having a heated argument, watching an action movie, drinking water that is very cold, experiencing prolonged sun exposure, working a long time in front of a computer, eating foods that are hard to digest, or taking a long, difficult walk.

With the activation of the RSR, the body’s usually precise balance is compromised because the sympathoadrenal system directs more blood to the brain in order to ensure the survival of the body. This can lead to wild 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 AFS 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.

Stressors That May Affect the RSR

Stressors don’t have to be physical in order to activate the RSR and the adrenal response. One study indicated that psychological stress can result in activation of the AHS, worsening risk of cardiovascular disease. This occurs because the release of adrenaline and norepinephrine, combined with continued psychological stress, can increase the risk of cardiovascular disease. This is apparent in professions where stress is an ingrained component.

Hypoglycemia is an adrenal responseIn patients with hypoglycemia, the SAS may serve as an early warning system for the body. Unfortunately, it’s also possible that the SAS may become blunted and less effective in this regard. If you experience this, you have a higher risk of issues with the central nervous system due to low blood sugar. The SAS seems to play a role in glucose sensing in the blood.

Repeated exposure to the metabolic stress brought on by hypoglycemia appears to decrease SAS responses. This may be due to a part of the brain called the posterior paraventricular nucleus of the thalamus. This structure appears to modulate the responses of the central nervous system to continuing stress, as is present in AFS.

Research has also shown the amount of catecholamines in the blood, such as adrenaline and norepinephrine, can predict elevations in blood pressure as long as 18 years after the upsurge of these chemicals. This finding could be significant in the development of essential hypertension, independent of the original blood pressure.

Resolving Adrenal Issues

When seeking ways to deal with the adrenal crashes seen with RSR and with AFS in general, it is important to seek out a healthcare professional who has the training and skills necessary for adequate assessment and resolution. A primary consideration is to give the professional plenty of time to make an accurate assessment of the adrenal responses. Once the effort to resolve the issues has begun, the process takes time. Possibly the most important consideration is to strictly follow the regimen directed by the healthcare practitioner.

Medications may be recommended, such as beta blockers, to control heart rate. This can often have short term benefit but long term can be very problematic. Caution is advised.

Reducing stress is the first step following the assessment. Stress is the overriding factor in the origin of both AFS and resulting RSR and RSO. This ongoing adrenal response overburdens the body’s ability to handle stress effects.

Any kind of stress can bring on the symptoms described above. If the source of stress in your life can be identified, do what is necessary to reduce it. In the case of not being certain of the stress in your life, take steps to relax and remove all stressors possible. Clearly, you can’t keep all stressors out of your life, but making the changes necessary to remove as many as possible is important.

One change you can make is to put as much positivity in your life as you can. Positive thoughts, positive sayings, and positive people can all reduce some of the negative factors that exacerbate stress.

Second, make changes in your diet. Foods you eat make a difference not just in your physical body, but also in your emotions. Eliminate foods that lead to inflammation and toxins in the body. Research is implicating inflammation in more and more of the physical issues people experience. Most people aren’t aware of the toxins they bring into their bodies through foods they eat and the environment in which they live and work. In both AFS and RSR, liver function may also be compromised. The liver is one of the main detox organs of your body.

An adrenal response can be triggered by caffeineOne major toxin is caffeine. Cutting down on coffee, tea, and chocolate can lower the amount of caffeine in your body. Caffeine makes it harder for you to sleep, and sleep is necessary to recover from stress.

Sugars in many forms are also toxins to your body. High fructose corn syrup and artificial sweeteners are especially toxic. These substances can produce an adrenal response, increasing inflammation in your body, potentially leading to serious disorders such as type 2 diabetes.

Microwaving and processing foods strips them of the nutrients your body needs. There have been indications that microwaving some foods also produces carcinogens. Fillers and preservatives added to food also can’t be digested by your body, resulting in significant loss of energy required during the attempted digestion.

You can also add foods and supplements to your diet to make a difference.

Supplements and herbs like holy basil, magnesium, vitamins B12, B5, D3, and C, ashwagandha, zinc, and fish oil are all beneficial nutritionally. Unfortunately, they can also be too stimulating for the body when it is already in a state of overdrive. You may need to be especially careful with herbs and glandulars, including ashwagandha. Symptoms can worsen in some cases. If you can get these substances from foods, that is the best source. If not, they can be taken as supplements.


If you experience the adrenal response symptoms discussed in this article, be sure to consult with a well-trained healthcare practitioner. Be ready to listen to your physician’s recommendations and give them plenty of time to work. You can change your health. All you have to do is make the right choices.

Adrenal response

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