Cortisol is often vilified as "the stress hormone," but this glucocorticoid is essential for life. We literally cannot survive without it. Problems arise not from cortisol itself, but from dysregulated cortisol patterns that disrupt virtually every body system.
Understanding cortisol—how it should work and what happens when it doesn't—is foundational knowledge for any functional medicine practitioner.
The HPA Axis: Your Stress Response System
Cortisol is produced through the Hypothalamic-Pituitary-Adrenal (HPA) axis. Here's how it works:
- The hypothalamus (in the brain) perceives a stressor and releases CRH (corticotropin-releasing hormone)
- CRH signals the pituitary gland to release ACTH (adrenocorticotropic hormone)
- ACTH travels through the bloodstream to the adrenal glands (sitting atop your kidneys)
- The adrenals respond by producing cortisol
- Rising cortisol levels feed back to the hypothalamus and pituitary to shut down the stress response
This elegant negative feedback loop evolved to handle acute stressors—a predator attack, a physical injury, a sudden threat. Cortisol mobilizes energy (glucose), sharpens focus, and modulates immune function to help us survive.
The problem: This system isn't designed for chronic activation. Constant work stress, inflammatory diets, sleep deprivation, and sedentary lifestyles keep the HPA axis firing continuously—and the system breaks down.
Healthy Cortisol Patterns: The Rhythm of Wellness
Cortisol follows a circadian rhythm that reflects healthy function:
- Highest in the morning — peaks around 30 minutes after waking (the "cortisol awakening response"), giving you energy to start the day
- Gradually declining through the day — a steady decrease as the day progresses
- Lowest at night — drops to allow melatonin to rise and sleep to occur
The cortisol awakening response (CAR)—that spike 30-45 minutes after waking—is actually a marker of healthy HPA function. It's your body's natural "wake up" signal. When this is blunted or absent, something is wrong.
Signs of Cortisol Dysregulation
High Cortisol Signs:
- Difficulty falling asleep (wired at night)
- Anxiety and racing thoughts
- Weight gain, especially around the midsection
- High blood pressure
- Blood sugar imbalances
- Frequent illness (immune suppression)
- Thinning skin, easy bruising
- Memory problems
Low Cortisol Signs:
- Difficulty waking up—hitting snooze repeatedly
- Afternoon energy crashes (especially 2-4 PM)
- Brain fog and poor concentration
- Low blood pressure, dizziness on standing
- Salt cravings
- Slow recovery from illness or exercise
- Low stress tolerance—small things feel overwhelming
Flattened Curve (Most Common):
Many chronically stressed individuals show a blunted pattern—relatively low morning cortisol that stays low all day, or slightly elevated but flat. They're tired but wired: exhausted yet unable to relax, running on adrenaline and caffeine.
Testing Cortisol: Getting Accurate Data
Four-point salivary cortisol testing captures the daily rhythm with samples at:
- Upon waking (before getting out of bed)
- Before lunch (late morning)
- Late afternoon
- Before bed
Some practitioners add a "post-awakening" sample (30 minutes after waking) to assess the cortisol awakening response.
DUTCH testing (Dried Urine Test for Comprehensive Hormones) provides even more detail, showing both cortisol production and metabolites. This can reveal whether low cortisol is due to underproduction or rapid clearance—which guides treatment differently.
Note: A single blood cortisol test is nearly useless for assessing HPA function. It only captures one moment and doesn't show the pattern.
Supporting Healthy HPA Function
Lifestyle Interventions (Most Important):
- Morning light exposure — get outside within 30 minutes of waking; sunlight helps set circadian rhythm
- Regular sleep-wake times — consistency matters more than duration
- Moderate exercise — intense exercise can worsen HPA dysfunction; gentle movement heals
- Blood sugar stabilization — eat protein and fat at each meal; avoid sugar crashes
- Stress-reduction practices — meditation, yoga, breathwork, time in nature
- Caffeine timing — avoid caffeine within 8-10 hours of bedtime; consider eliminating it during healing
Nutritional Support:
- B vitamins — especially B5 (pantothenic acid), essential for cortisol production
- Vitamin C — heavily used by the adrenal glands; depleted by stress
- Magnesium — "the relaxation mineral"; depleted by stress and needed for HPA regulation
- Omega-3 fatty acids — anti-inflammatory; support healthy cortisol response
Adaptogenic Herbs:
- Ashwagandha — lowers elevated cortisol; particularly good for anxious, wired types
- Rhodiola — supports stress resilience; helpful for fatigue with preserved function
- Holy basil (Tulsi) — calming adaptogen; good for anxiety and sleep
- Licorice root — slows cortisol breakdown (use cautiously; contraindicated in high blood pressure)
- Eleuthero — gentle adaptogen; good for sustained energy without stimulation
These interventions work best as part of a comprehensive plan addressing the underlying stressors driving HPA dysfunction. You can't supplement your way out of a stressful lifestyle.
The Bottom Line
Understanding cortisol patterns is foundational to functional medicine practice. Nearly every chronic condition involves some degree of HPA axis involvement—whether as a cause or consequence. When you learn to assess and support this system, you unlock healing for conditions that otherwise seem intractable.
The goal isn't to eliminate cortisol—it's to restore the healthy rhythm that allows for energy when you need it and rest when you don't.
