Our Services
Medical Information
Helpful Resources
Published on: 2/27/2026
Constant tiredness can result from high cortisol, which disrupts sleep and blood sugar and keeps the nervous system activated; common drivers include chronic stress, poor sleep, overtraining, blood sugar swings, some medications, and conditions like Cushing syndrome, though low cortisol can cause similar symptoms.
Medically approved next steps include confirming levels with doctor-ordered tests, then improving sleep, stabilizing blood sugar, adjusting exercise, using proven stress reduction, and reviewing medications, with urgent care for red flags such as rapid weight gain, severe weakness, or very high blood pressure. There are several factors to consider, see below for details that can change which next steps are right for you.
If you feel exhausted no matter how much you sleep, your cortisol levels may be part of the picture.
Cortisol is often called the "stress hormone," but that label doesn't tell the whole story. Cortisol is essential for life. It helps regulate:
Problems happen when cortisol levels stay too high for too long — or, in some cases, when they drop too low. Both situations can make you feel persistently tired.
Let's break down why high cortisol levels can leave you drained, what causes it, and what medically sound next steps look like.
Cortisol follows a natural daily rhythm (called a diurnal rhythm):
Healthy cortisol levels rise and fall predictably. When that rhythm is disrupted — or when levels remain elevated — your body can feel constantly "on," even when you're exhausted.
It sounds backwards. If cortisol helps you stay alert, why would high cortisol levels cause fatigue?
Because chronic stress hormones exhaust the body over time.
When cortisol stays elevated:
Over time, this leads to:
This isn't weakness. It's biology.
Several medically recognized factors can raise cortisol levels.
Work pressure, financial strain, caregiving, trauma, and ongoing anxiety can all drive sustained cortisol elevation.
Sleep deprivation increases evening cortisol, which then disrupts sleep again — creating a cycle.
Excessive high-intensity exercise without recovery can push cortisol levels up.
Frequent spikes and crashes (from high-sugar diets or skipped meals) stimulate cortisol release.
Some conditions directly increase cortisol levels, including:
Certain medications, especially long-term steroid use (like prednisone), can also affect cortisol balance.
High cortisol levels do not always cause obvious symptoms at first. When they do, they may include:
If symptoms are significant or worsening, medical evaluation is important.
Sometimes, extreme fatigue is not from high cortisol levels — but from low cortisol, a serious medical condition known as adrenal insufficiency (including Addison disease).
Low cortisol can cause:
Adrenal insufficiency can become life-threatening if untreated. If you're experiencing several of these symptoms and want to understand whether they could point to Adrenal Insufficiency (e.g. Addison Disease), a free AI-powered symptom checker can help you assess your risk and determine how urgently you should seek medical care.
If high (or low) cortisol levels are suspected, a doctor may order:
Testing is important because symptoms alone cannot determine whether cortisol levels are high, low, or normal.
Avoid self-diagnosing based on internet advice or at-home hormone panels without medical guidance.
If testing confirms elevated cortisol — or if stress is the likely cause — evidence-based steps can help regulate cortisol levels safely.
Sleep is the most powerful cortisol regulator.
Focus on:
Even modest sleep improvement can normalize cortisol levels within weeks.
To prevent cortisol spikes:
Balanced blood sugar reduces stress hormone activation.
Exercise lowers long-term cortisol levels — but too much high-intensity training can increase them.
Aim for:
If you feel worse after workouts, scale back temporarily.
You don't need extreme lifestyle changes. Consistency matters more than intensity.
Evidence-based methods include:
These approaches measurably reduce cortisol levels over time.
Some prescriptions affect cortisol balance. Never stop a medication on your own — but ask your doctor if adjustments are appropriate.
If you have:
You should speak to a doctor promptly. These could signal serious hormonal disorders that require medical treatment.
Be cautious of:
Many over-the-counter products claim to "fix cortisol levels" but lack strong scientific evidence.
You should speak to a doctor if:
If symptoms feel sudden, severe, or life-threatening, seek urgent medical care.
Hormonal disorders are treatable — but proper testing is essential.
High cortisol levels can absolutely make you feel constantly tired. Chronic stress, poor sleep, blood sugar swings, overtraining, and medical conditions all play a role.
The good news:
If you're unsure whether your symptoms suggest high cortisol levels or possibly low cortisol, an online symptom assessment for Adrenal Insufficiency (e.g. Addison Disease) can help you understand your symptoms better before seeing a doctor.
Then take the most important next step: speak to a qualified doctor. Persistent fatigue is not something you should ignore — and you deserve clear answers and appropriate care.
Your body isn't failing you. It's signaling that something needs attention.
(References)
* Morris, G., Berk, M., Walder, K., & Maes, M. (2021). The neurobiology of chronic fatigue syndrome: a systematic review. *Journal of Translational Medicine*, *19*(1), 1-14.
* Steudte-Schmiedgen, S., Kirschbaum, C., & Alexander, N. (2020). The impact of chronic stress on health: New insights and future directions. *Psychoneuroendocrinology*, *118*, 104711.
* Chrousos, G. P., Gold, P. W., & McEwen, B. S. (2020). Hypothalamic-Pituitary-Adrenal Axis Dysfunction and Chronic Fatigue Syndrome: Neuroendocrine, Neuroinflammatory, and Neuroimmune Interactions. *Journal of Clinical Endocrinology & Metabolism*, *105*(7), dgaa217.
* O'Connor, A., Alexander, N., & Kirschbaum, C. (2018). Lifestyle and HPA Axis Regulation: Implications for Stress-Related Disorders. *Stress*, *21*(6), 567-578.
* Schultze-Lutter, F., Schimmelmann, B. G., & Michel, C. (2018). The effect of mindfulness-based stress reduction on salivary cortisol: A systematic review and meta-analysis. *Neuroscience & Biobehavioral Reviews*, *85*, 24-34.
We would love to help them too.
For First Time Users
We provide a database of explanations from real doctors on a range of medical topics. Get started by exploring our library of questions and topics you want to learn more about.
Was this page helpful?
Purpose and positioning of servicesUbie Doctor's Note is a service for informational purposes. The provision of information by physicians, medical professionals, etc. is not a medical treatment. If medical treatment is required, please consult your doctor or medical institution. We strive to provide reliable and accurate information, but we do not guarantee the completeness of the content. If you find any errors in the information, please contact us.