Foundations
What Is Cortisol? The Complete Guide
The stress hormone, its daily rhythm, and what high and low levels feel like — start here.
Read guide → RhythmThe Cortisol Curve & Circadian Rhythm
What a healthy diurnal cortisol pattern looks like and how to read the shape of yours.
Read guide → RhythmCortisol Awakening Response (CAR)
The morning cortisol spike that sets your energy for the day — and why it matters.
Read guide → SymptomsHigh Cortisol Symptoms & Cortisol Face
Wired but tired, poor sleep, midsection weight, and the "cortisol face" trend — decoded.
Read guide → SymptomsLow Cortisol & Adrenal Fatigue
Deep exhaustion, morning sluggishness, and brain fog — what a flat cortisol curve feels like.
Read guide → TestingCortisol Testing Guide
Saliva, DUTCH, blood, and 4-point cortisol tests compared — which to choose and how to read them.
Read guide →Cōrta can help
Put the science into practice
Reading about cortisol is step one. Cōrta lets you actually track your rhythm — logging symptoms, syncing HRV and sleep, and showing which habits move your curve.