Overwhelm.
Tension.
Brain Fog.
Headaches.
Exhaustion.
Sugar Cravings.
These common symptoms are red flags indicating your body may have an altered stress response. Understanding why this happens and what to do can be key to taking control of your health. Read on the learn more.
The Stress Response
Our stress response is a natural, built-in mechanism designed to give us the energy and attention to rise to the occasion - whether it's meeting a work deadline or catching a child running into traffic - with a return to normal after the stressful event passes.
While this response is effective for short bursts of time, or acute stress, problems arise when we are chronically stressed or worried. Chronic stress continually triggers the body's stress response, keeping us in fight-or-flight mode longer than the system is designed to support.
The link between high levels of stress and negative health outcomes is well established, which is why it's important to be aware of your stress levels and how to manage them. Before discussing the signs of an altered stress response, let’s take a look at the hormonal and physiological changes that make up the stress response.
What Happens During the Stress Response
The stress response begins in the brain and is carried out via a cascade of events (think about the game of telephone) through the neuroendocrine network called the HPA (hypothalamus-pituitary-adrenal) axis. The cascade starts with the amygdala and ends with the adrenal glands.

Let’s break it down by step-by-step:
1. The Amygdala
When a threat (or stressor) is present, the eyes and ears send sensory information to the amygdala, a part of the brain responsible for processing strong emotions such as fear, pleasure and anger. The amygdala analyzes this information and, during a stressful event, sends a distress signal to the hypothalamus that there is a problem[1].
2. The Hypothalamus
Located just above the brain stem, the hypothalamus acts as the control center of the brain, taking in internal and external signals and regulates the release of hormones from the pituitary gland. In a stress situation, the hypothalamus releases corticotropin-releasing hormone (CRH) which signals the pituitary gland to step up to the plate to activate the rest of the body.
3. The Pituitary Gland
The pituitary gland is a pea-sized gland located at the base of the brain responsible for regulating growth and hormonal production. In response to CRH from the hypothalamus, the pituitary releases adrenocorticotropic hormone (ACTH) into the bloodstream that activates the adrenal glands.
4. The Adrenal Glands
These are almond-sized glands located on the top of the kidneys responsible for a wide variety of hormonal production. ACTH travels to the adrenal glands triggering the release of the main stress hormone, cortisol, along with the stimulatory neurotransmitter, adrenaline. This signals time to FIGHT or RUN!
Suddenly the body is in stress response mode:
- The heart beats faster to deliver extra blood to the heart, muscles, and organs.
- Breathing quickens to deliver oxygen to tissues
- Blood vessels constrict, raising blood pressure and driving blood to essential tissues
- Glucose is released from the liver, raising blood sugars, to fuel the brain and muscles
All of these changes you may be aware of but have no control over. That is because the stress response is controlled by the autonomic nervous system (ANS) — think “automatic” bodily functions (e.g., breathing, heart rate, constriction/dilation of blood vessels). The ANS has two parts: the sympathetic nervous system and the parasympathetic nervous system. The sympathetic triggers the "fight or flight" response while the parasympathetic signals to "rest and digest".
The stress response produces fight or flight effects lasting for short periods of time. Once the stressor has passed, the parasympathetic branch kicks in to bring the body back to equilibrium - rest, digest, heal, calm.
The problem arises when the stress signal is unrelenting. In the face of constant threats and chronic problems, the body stays in an activated state. Elevated levels of epinephrine, cortisol, and blood sugar, coupled with an increased heart rate and high blood pressure, have negative health consequences. Let’s take a look at some signs your body may be stuck in an altered stress response.
Signs Your Body is Stressed
Signs that can indicate an altered stress response can be gathered from multiple areas including:
- Symptoms: this includes things you may observe and experience outside of your normal baseline such as fatigue, feeling anxious or tense, headaches, racing heart, and brain fog.
- Biomarkers: this includes measuring different stress hormones and nutrients via blood or salivary samples that can indicate where you are at in the stress response.
- Biometrics: this includes tracking different aspects of the stress response such as sleep quality and heart rate variability via wearable technology including watches, rings, apps, and more.
Let’s breakdown each of these areas, what they mean regarding an altered stress response, and what you can do to take control of your stress.
Stress Symptoms
Low energy levels
Prolonged stress depletes daily energy levels. There are multiple ways it can affect energy throughout the day:
- Inhibited executive functioning from prefrontal cortex (e.g., decision making, attention) due to prolonged elevated cortisol
- Depletion of nutrients such as B vitamins and magnesium that are used to create cellular energy in the form of ATP during a prolonged stress response.
- Down-regulated mood, energy and motivation due to decrease in serotonin and dopamine production.
Appetite changes
Changes in appetite, either loss of appetite or overeating, may be due to stress. Every body reacts differently to stress. Some individuals are drawn to overeating as a mode of comfort while others forget to eat and not only lose weight but become nutrient deficient.
The physiology behind appetite changes can be understood by the following:
- A decrease in appetite can occur when the adrenal glands release cortisol and epinephrine. These stress hormones trigger the liver to release stored glucose into the bloodstream, thus decreasing hunger signals.
- Cravings for sugar and simple carbohydrates arise as chronic stress progresses. Cortisol and glucose levels can begin to fluctuate and lead to blood sugar imbalances. These rises and falls in blood sugar can trigger cravings for sugar due to their ability to quickly raise blood sugars and boost feel-good neurotransmitters such as serotonin.
- A lack of desire for food or changes in food preferences can occur as stress negatively impact digestion, health of the gut lining and increase the chances of food sensitivities and allergies.
- Hunger and satiety signals can become disrupted due to alterations in leptin and ghrelin production, hormones responsible for hunger and fullness cues. Leptin, the hormone that makes you feel full, is lowered following a stressful event [8].
Headaches
Frequent unexplained headaches may be a physical symptom of an altered stress response.
Stress headaches can occur for multiple reasons due to changes in physiology including:
- High levels of adrenaline in the bloodstream
- Increased inflammation and oxidative stress
- Muscle tension in the neck and shoulders or a clenched jaw
- High blood pressure from chronic vasoconstriction and nervous system stimulation
- Improper hydration and poor electrolyte status
It is important to pay attention to the signs and symptoms of stress you experience and share them with your healthcare professional.
Stress Biomarkers
There are several biomarkers that can be helpful in assessing an altered stress response and how to recover. These include 1) cortisol, a key stress hormone 2) DHEA, an upstream hormonal precursor made by the adrenal glands 3) micronutrients used in a stress response such as magnesium, B6, B12, vitamin C, and vitamin D.
Cortisol
Cortisol is a glucocorticoid hormone, a type of steroid hormone, responsible for regulating your body’s stress response, suppressing inflammation, and regulating blood pressure and blood sugar. It also helps with the metabolism of nutrients and affects your sleep-wake cycle.
Almost every tissue in your body has a receptor for cortisol. It's important to check cortisol levels through either a salivary, blood, or urine test to gauge the body's stress levels.
Cortisol peaks in the morning and then drops throughout the day, hitting its lowest point at midnight. Because of this, samples are typically taken in the morning. For a more comprehensive view, multiple samples are taken throughout the day — waking, mid-day, and evening.
Low cortisol
Low cortisol levels (hypocortisolism) is considered adrenal insufficiency [11]. This can be caused by an autoimmune condition (Addison's disease), an under-active pituitary gland and other health conditions including long haul COVID.
Weakness, fatigue, low appetite, weight loss, or low blood pressure can be physical symptoms of low cortisol production.
High cortisol
High cortisol is usually classified as Cushing's disease. It could also point to the presence of neuroendocrine tumors.
Weight gain, high blood pressure, high blood sugar (diabetes), excessive hair growth, or weak bones are physical symptoms of high cortisol [11].
DHEA
Dehydroepiandrosterone (DHEA) is an upstream corticosteroid made by the adrenal glands that acts as a precursor for several key hormones including testosterone, estrogen, and progesterone. DHEA levels tend to peak around 25 years of age and decline into later adulthood. DHEA can be used to measure the severity of an altered stress response via alternations in the HPA axis and DHEA production from the adrenal glands. DHEA-S levels can be assessed through blood or saliva.
Symptoms of low DHEA include: Fatigue, muscle loss, loss of bone density, low libido, joint pain, weight gain, depression, and decreased immunity.
Micronutrients
Measuring micronutrient status can be helpful for supporting a healthy stress response and recovering from prolonged periods of stress.
Vitamin B12
B12 is a major player in the stress response due to its role in nervous system health: energy, mood, hormone production, inflammation, and oxygen delivery via red blood cells. Demands for B12 can increase during times of stress and supplementation has been shown to improve resiliency and depressive symptoms. Optimizing B12 status can help counteract the negative effects of stress.
Stress can directly impact the absorption of vitamin B12 and lead to lower blood levels due to a down regulation in gastric secretions. B12 is absorbed when special cells in the stomach, parietal cells, make a compound called intrinsic factor that allows B12 to cross into the bloodstream.
Vitamin B6
Vitamin B6 has many roles that are relevant to the stress response including immune system function (antibody production), balancing blood sugars, making neurotransmitters (GABA, serotonin, dopamine) for mood regulation, and oxygen transport via hemoglobin production.
Randomized control trial studies have demonstrated vitamin B6 as an effective tool to improve anxiety and depression symptoms in stressed healthy adults. Inadequate intake of vitamin B6 was shown to increase the risk of anxiety and depression in 3000 adults. B6 works synergistically with magnesium and may enhance the absorption and effects of magnesium.
Magnesium
Magnesium is a critical co-factor in over 300 biochemical pathways and is important for heart health, blood pressure, brain health (acts as a brake to calm the nervous system down), blood sugar balance, digestive tract, and DNA & RNA health.
Did you know your need for magnesium can DOUBLE under stress or that stress depletes magnesium? Ever notice your eye twitching, feel heart palpitations, or jump out of bed with a charlie horse in your leg? These are all signs that you may have suboptimal magnesium levels.
Vitamin C
Vitamin C is commonly known as an antioxidant meaning it functions to reduce the amount of free radicals that lead to inflammation and tissue damage. While this is true, vitamin C is also a superhero for stress support. Studies have shown getting adequate amounts of vitamin C can lower stress hormones in the blood, improve sense of wellbeing via dopamine production, aid in weight loss, improve the health of the adrenal glands and immune system.
Vitamin D3
Often referred to as “The Stress Quenching” vitamin due to its ability to inhibit metabolic stress signals at a cellular level, vitamin D is a pro-survival agent during times of intense and prolonged stress.
Mental health can suffer during times of intense and chronic stress. Vitamin D3 has been shown to improve mood, fatigue and sense of wellbeing in study participants, especially those deficient in this vitamin. Vitamin D3 may also help with bone loss prevention during chronic stress and improve immune system function.
Vitamin D3 (VD) is as fat-soluble vitamin that has a very similar chemical structure to many hormones, and in fact tends to function like a hormone in the body. VD functions include bone health, immune health, inflammatory control (lowers CRP) and brain health. Optimal blood levels for vitamin D3 range from 40-60ng/mL.
Stress Biometrics
Biofeedback is a non-invasive way to assess the physiological response and health of your body. Looking at heart rate variability (HRV), resting heart rate, and sleep quality can shed light on how your body handles stress.
HRV

One biofeedback measurement tool is HRV, or heart rate variability, the variance in time between each heartbeat. You can track HRV with a wearable device. Ideally, the time between each beat should vary (e.g., 1.3 seconds between beats, followed by 0.9 seconds between beats). "The greater this variability is, the more ready your body is to execute at a high level" [3].
This relates to the parasympathetic and sympathetic branches of the autonomic nervous system. The sympathetic "fight or flight" activation will increase heart rate, while the parasympathetic "rest and digest" activation will slow heart rate, thus affecting HRV.
Although it may seem counterintuitive (because many assume both heart rate and HRV should be steady and consistent), HRV is supposed to fluctuate throughout the day as there should be times when you're relaxed and then times you're body is under stress, like when exercising.
High HRV means your heart is receptive to input from both sympathetic and parasympathetic branches of the nervous system. It indicates a balance between them.
Low HRV can indicate one side is dominant over the other, usually sympathetic. This could be a sign your body is continually mounting a stress response; an increase in the sympathetic-to-parasympathetic ratio is linked to increased cardiovascular morbidity and mortality [4].
Resting heart rate
Resting heart rate is how many times your heart beats per minute at rest. The healthy range is between 60-100 beats per minute. Very healthy individuals, like long-distance runners, can have a resting heart rate as low as 40.
Factors that affect resting heart rate include circulating hormone levels, physical fitness, and autonomic nervous system health.
In a stressful situation, your heart rate might speed up. But by the end of it, it should return back to normal. An elevated heart rate for a prolonged amount of time is a sign your body may have an altered stress response.
Check your heart rate
Many health devices can be worn to monitor heart rate. It's also easy to check it yourself. Using your pointer finger and index finger, place them on the opposite wrist just below the base of the thumb or on the side of the neck just below the jawbone. You should be able to feel each beat; count the beats in 15 seconds, and then multiply by four to get your heart rate.
If you suspect you have an elevated heart rate, it's important to go to the doctor to rule out other health conditions.
Sleep quality

It's no surprise that sleep quality and stress levels have an inverse relationship.
The sleep-stress cycle refers to the bidirectional relationship between sleep and stress: sleeping less increases stress levels the next day, and increased stress levels decrease sleep quality. It's a negative cycle that perpetuates the problem.
This is because sleep and stress share the same pathway: the HPA axis. Studies show that an overactive HPA axis is linked with decreased sleep quality and amount [6], and that the day after a rough night of sleep, your body produces higher amounts of cortisol.
In a sleep-stress study, The American Psychological Association found that "adults who sleep fewer than eight hours a night are more likely to report symptoms of stress in the past month". They also concluded that "adults with lower reported stress levels report sleeping more hours a night than do adults with higher reported stress levels" [5].
If you find yourself having a hard time falling asleep or staying asleep, it could be a sign of HPA axis dysregulation, meaning the body is not relaxed enough to enter a deep sleep state.
Take Control of Your Stress
Encountering stressors throughout daily life is unavoidable. However, managing stress is something you can control. Below are some ways you can improve your body's ability to handle stress.
Sleep
Considering how strongly sleep and stress are linked, it's important to prioritize rest. While it's recommended to sleep 7-9 hours per night, many Americans sleep 6 hours or less.
Tips to improve sleep quality and quantity:
- Go to bed and waking up at similar times each day
- Lower light exposure before bed from bright lights and screens
- Get outside: Exposure to full spectrum sunlight in the morning causes our brains to produce serotonin, stops the production of melatonin, and resets your circadian rhythm
- Do something calming before bed like taking a hot shower, reading, or meditating
Nutrition

Diet plays a big role in how we feel. As discussed, stress responses can alter our appetite and what foods we crave.
Research shows that elevated cortisol combined with high sugar consumption "may prompt the deposition of fat around our internal organs-visceral fat that is associated with cardiovascular and metabolic diseases" [9].
Eating a variety of nutrients can help regulate blood sugar (which is more sensitive when stressed) and ensure your body is getting the nutrients it needs.
Eat the Rainbow. The color in food displays the wide variety of plant chemicals that nourish cells and fight inflammation. Aim to eat 20 different plant species per week.
Protein is key for balancing blood sugar. Aim for a serving of lean protein at each meal to support consistent energy levels.
Physical activity
Regular physical exercise can improve sleep and decrease overall stress. Exercise lowers levels of adrenaline and cortisol while also stimulating the production of endorphins, feel-good chemicals in the brain.
Reframe your thinking
Lastly, checking in with your mindset is important. A research-supported tool for stress is CBT, or cognitive behavioral therapy. This approach is based on the process that thoughts affect emotions which affect actions. "Reframing your thoughts around a stressor can help manage your emotions, reducing feelings of stress" [10].
This could look like being aware of how worst-case scenario thinking affects stress levels and trying to reframe to more positive thoughts. If additional support is needed, seek out a professional mental health provider who can help with stress management.
It’s important to remember stress is a common denominator for all of us. If you believe you have an altered stress response from chronic stress, there are many things you can do to bring your body and mind back to balance.
Sources
- Understanding the stress response. Harvard Health. (2020, July 6). Retrieved July 25, 2022, from https://www.health.harvard.edu/staying-healthy/understanding-the-stress-response
- Cortisol: What it is, function, symptoms & levels. Cleveland Clinic. (2021). Retrieved July 26, 2022, from https://my.clevelandclinic.org/health/articles/22187-cortisol
- Heart rate variability: The ultimate guide to HRV. WHOOP. (2021, August 11). Retrieved July 25, 2022, from https://www.whoop.com/thelocker/heart-rate-variability-hrv/
- Schubert, C., Lambertz, M., Nelesen, R. A., Bardwell, W., Choi, J.-B., & Dimsdale, J. E. (2009, March). Effects of stress on heart rate complexity--a comparison between short-term and chronic stress. Biological psychology. Retrieved July 25, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2653595/
- American Psychological Association. (2013). Stress and sleep. American Psychological Association. Retrieved July 26, 2022, from https://www.apa.org/news/press/releases/stress/2013/sleep
- Buckley, T. M., & Schatzberg, A. F. (2005, May 1). On the interactions of the hypothalamic-pituitary-adrenal (HPA) axis and sleep: Normal HPA Axis activity and circadian rhythm, exemplary sleep disorders. OUP Academic. Retrieved July 25, 2022, from https://academic.oup.com/jcem/article/90/5/3106/2837129
- Why stress causes people to overeat. Harvard Health. (2021, February 15). Retrieved July 25, 2022, from https://www.health.harvard.edu/staying-healthy/why-stress-causes-people-to-overeat
- Bouillon-Minois, J.-B., Trousselard, M., Thivel, D., Benson, A. C., Schmidt, J., Moustafa, F., Bouvier, D., & Dutheil, F. (2021, September 24). Leptin as a biomarker of stress: A systematic review and meta-analysis. Nutrients. Retrieved July 25, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8541372/
- Thorn , B. (2013, November). Healthy ways to handle life's stressors. American Psychological Association. Retrieved July 25, 2022, from https://www.apa.org/topics/stress/tips
- American Psychological Association. (2019, October). Manage stress: Strengthen your support network. American Psychological Association. Retrieved July 26, 2022, from https://www.apa.org/topics/stress/manage-social-support
- Cortisol: What it is, function, symptoms & levels. Cleveland Clinic. (n.d.). Retrieved July 26, 2022, from https://my.clevelandclinic.org/health/articles/22187-cortisol