Cortisol is often misunderstood as simply the ‘stress hormone’, but it plays a fundamental role in how the body responds to its environment. It helps regulate metabolism, inflammation, blood sugar, and most importantly, the body’s ability to manage stress.

Ideally, cortisol follows a natural daily rhythm, rising in the morning to help us wake up and gradually decreasing in the evening to allow the body to rest and recover. However, in today’s fast-paced, high-pressure society, chronic stress keeps cortisol levels elevated for extended periods, leaving the nervous system stuck in a persistent state of survival mode.

As human beings, our primary role is survival. Therefore, if we are always constantly living in a survival response pumping out cortisol, the focus is on surviving, not healthy systems in the body. Over time, this dysregulation leads to serious consequences, affecting the brain, immune system, digestion, hormones, and long term health.

If left unchecked, it can push the body towards burnout, where cortisol eventually crashes, leading to severe exhaustion, emotional detachment, and systemic dysfunction. 

Here are 10 key signs that your cortisol levels are too high and how they may be affecting your nervous system and overall health…

1. You Wake Up Tired, Even After a Full Night’s Sleep

Cortisol is supposed to peak in the morning to help you wake up feeling refreshed. If you struggle to get out of bed despite 7–9 hours of sleep, it’s a clear sign that your cortisol rhythm is off. Instead of following its natural cycle, your body may be producing cortisol at the wrong times. Too much at night when you’re supposed to be winding down, and too little in the morning when you need energy. This disruption can leave you feeling groggy all morning but wired and restless at night, reinforcing a vicious cycle of fatigue and overstimulation.

2. You Feel Constantly Anxious or On Edge

Chronic high cortisol keeps the nervous system stuck in a fight-or-flight response, making it difficult to relax. This can show up as racing thoughts, a sense of doom, restlessness, and overreacting to small stressors. Even in moments of quiet, the body remains hypervigilant, scanning for potential threats. Over time, this constant state of alertness leads to burnout, increased heart rate, and adrenal fatigue, making it harder for the body to return to balance.

3. Your Digestion is Unpredictable (Bloating, IBS, Constipation, or Diarrhoea)

Cortisol and digestion are directly linked because the nervous system controls gut function. When cortisol is high, digestion slows down or even shuts off completely, and if the body thinks it’s in danger, digesting food is not the priority. This can cause bloating, stomach pain, constipation, or diarrhoea, even when no dietary changes have been made. Over time, chronic stress can damage gut bacteria, lower stomach acid production, and increase inflammation, contributing to conditions like irritable bowel syndrome (IBS) and leaky gut. It can also lead to struggling to lose weight as the body wants to hold on to excess fat stores, in case the body needs it for “survival”.

4. You Crave Sugar and Have Blood Sugar Crashes

Cortisol increases blood sugar levels to prepare the body for immediate action. In a survival situation, having a sugar fix provides quick energy for running or fighting. But when cortisol is consistently high, it creates blood sugar instability, leading to strong cravings for sugar and processed carbohydrates. These cravings may seem random, but they are the body’s way of trying to restore balance. Frequent blood sugar spikes and crashes can increase the risk of insulin resistance, weight gain, and mood swings.

5. You Struggle with Brain Fog and Poor Memory

Cortisol affects the hippocampus, the brain’s memory and learning centre. Chronically high levels interfere with concentration, mental clarity, and recall, making it harder to focus on tasks or retain information. Many people with high cortisol describe feeling mentally sluggish, forgetful, or unable to stay present, as if their brain is constantly running on low energy. This foggy state is a direct result of the nervous system prioritising survival over cognitive function.

6. Your Immune System is Weaker Than Usual

In small doses, cortisol is anti-inflammatory, helping the body recover from injury or infection. However, when it remains elevated for too long, it suppresses immune function, making you more vulnerable to frequent colds, infections, and even autoimmune flares. If you’re constantly getting sick, struggling with slow recovery, or experiencing worsening symptoms of an autoimmune condition, high cortisol could be depleting your immune resilience.

7. Your Muscles Feel Weak, and You Struggle to Recover from Exercise

Cortisol breaks down muscle tissue as a way to provide energy in times of stress. If your cortisol levels are persistently high, your body prioritises survival over muscle repair, leading to muscle loss, weakness, and slower recovery from exercise. Even if you work out regularly, you may find that your strength is plateauing, or that soreness lingers far longer than it should.

8. You Experience Hormonal Imbalances (Low Libido, Irregular Periods, or Thyroid Issues)

Cortisol competes with sex hormones like oestrogen, progesterone, and testosterone, meaning that when stress is high, reproductive function is often deprioritised. This can lead to irregular or painful periods, low libido, worsened PMS, and even fertility challenges. Additionally, high cortisol suppresses thyroid function, leading to symptoms like weight gain, fatigue, and cold intolerance.

9. You Feel Exhausted During the Day but Wired at Night

Cortisol should follow a natural daily rhythm, but chronic stress can flip this cycle upside down. Many people with high cortisol feel drained all day, relying on caffeine to push through, only to feel wide awake when they try to sleep. This happens because cortisol remains high at night, preventing the natural rise of melatonin (the sleep hormone). If you regularly wake up at 2–4 AM feeling restless, this is a strong sign that your cortisol levels are out of sync.

10. You Feel Emotionally Numb, Depressed, or Disconnected

After prolonged stress exposure, the nervous system shuts down as a protective mechanism. While early signs of high cortisol include anxiety and hypervigilance, later stages often present as emotional numbness, lack of motivation, and depression. This happens because the body can no longer sustain high cortisol output, leading to burnout and a state of nervous system collapse. People in this phase often describe feeling detached from their emotions, unable to enjoy things they once loved, and struggling to find energy for daily life.

How to regulate your cortisol for long-term health

Cortisol is not the enemy, but in modern society, chronic stress keeps it elevated beyond what the body can handle. This leads to a cascade of nervous system dysfunction, contributing to long-term health issues that many people fail to connect to stress. The key to regulating cortisol isn’t about “reducing stress” in the traditional sense, it’s about teaching the nervous system how to feel safe again. Somatic practices, breathwork, nervous system regulation, and movement can all play a role in resetting the body’s natural rhythms and breaking free from survival mode. By recognising the early signs of cortisol dysregulation and taking action to restore balance, we can prevent burnout, chronic illness, and long-term damage to our health.

Caroline Strawson is a globally recognised Mental Health and Nervous System Educator and Therapist. More information can be found on her website: www.carolinestrawson.com