Cortisol, often called the "stress hormone," is produced by your adrenal glands and plays a pivotal role in regulating metabolism, immune response, blood pressure, and the sleep-wake cycle.
When cortisol is balanced, it helps your body respond to stress and maintain homeostasis.
However, when levels are chronically too high or too low, the effects can be profound and far-reaching.
High Cortisol: When the Stress Response Goes Into Overdrive
Excess cortisol is most famously associated with Cushing's syndrome, but even without this rare disorder, persistently high cortisol can disrupt multiple systems.
According to Dr. Theresa Larkin, chronic stress and dysregulated cortisol secretion can lead to a host of symptoms, including:
- Weight gain, especially around the abdomen, face, and upper back—even if eating habits haven't changed.
- Skin changes such as thinning, easy bruising, and purple stretch marks. Increased facial hair in women (hirsutism) and hair loss can also occur.
- Muscle weakness and fatigue, particularly in the shoulders, hips, and thighs, making everyday movements more difficult.
- Mood disturbances like anxiety, depression, mood swings, and trouble concentrating. At least half of people with Cushing's syndrome develop major depressive disorder.
- Reproductive changes, including irregular periods and reduced fertility in women.
- Hypertension and diabetes due to cortisol's impact on metabolism and blood sugar regulation.
Low Cortisol: When the Body's Alarm System Fails
Insufficient cortisol production, as seen in Addison's disease and certain chronic illnesses, can be equally debilitating. Recent research led by Matthew Frank, Senior Research Associate, found that low cortisol may underlie the persistent fatigue, brain fog, and neuroinflammation seen in long COVID and chronic fatigue syndrome.
Key symptoms of low cortisol include:
- Severe fatigue that doesn't improve with rest.
- Unintentional weight loss and loss of appetite.
- Low blood pressure, sometimes causing dizziness upon standing.
- Muscle and bones breakdown, leading to weakness and increased risk of injury.
- Memory impairments and cognitive difficulties, sometimes described as "brain fog".
- Widespread pain and increased sensitivity to stressors, both physical and psychological.
The Inflammation Connection: Cortisol as the Body's Firefighter
Cortisol's anti-inflammatory properties are essential for keeping immune responses in check. When cortisol is out of balance, inflammation can run rampant, contributing to conditions such as rheumatoid arthritis, fibromyalgia, and even depression. Dr. Larkin emphasizes that chronic inflammation from cortisol dysfunction can accelerate aging, increase oxidative stress, and damage tissues throughout the body.
Diagnosing Cortisol Imbalance: Why Symptoms Alone Aren't Enough
Self-diagnosing cortisol imbalance based on symptoms is unreliable. Cortisol levels fluctuate naturally throughout the day, peaking in the early morning and dipping at night. Laboratory testing of blood, or saliva is required for accurate assessment, and even then, interpretation is complex. Dr. Larkin cautions that routine testing is not recommended unless a clear clinical suspicion exists, as both high and low cortisol disorders are relatively rare.
Restoring Balance: Evidence-Based Strategies
While cortisol imbalances can be caused by underlying medical conditions requiring specialist care, lifestyle interventions remain foundational for most people:
- Stress management through mindfulness, meditation, and cognitive behavioral therapy can help recalibrate the stress response.
- Regular exercise and good sleep hygiene support healthy cortisol rhythms.
- Balanced nutrition provides the building blocks for optimal hormone production.
Cortisol imbalances are complex and can manifest in diverse, sometimes subtle ways. As Dr. Matthew Frank notes, "Cortisol has so many beneficial properties that, if it is reduced, it can have a host of negative consequences." Understanding the signs, seeking expert evaluation, and addressing both medical and lifestyle factors are key to restoring balance and protecting long-term health.
