How does the HPA axis work?
The hypothalamus-pituitary-adrenal (HPA) axis is a central pathway of the stress response. When faced with stress, CRH is secreted from the hypothalamus, which stimulates ACTH from the pituitary, then cortisol is released from the adrenal glands. Short-term cortisol is beneficial — it mobilizes energy, reduces inflammation. Chronic cortisol is harmful — it suppresses collagen synthesis, creating an anti-inflammatory but repair-inhibiting environment in the skin.
Stress symptoms on the skin
Typical packages found in patients under chronic stress in the clinic: low radiance, more pronounced dull/tired appearance, early fine line formation (especially in the glabella and between the eyebrows), increased general sensitivity, acne or rosacea flare-ups, hair loss (telogen effluvium).
Evidence-based stress management
Meditation and mindfulness: 10-15 minutes of mindfulness exercises daily can reduce cortisol by 15-20%. Skin effects can be measured in 6-8 weeks.
Breathing exercises (box breathing, 4-7-8 technique): activate the parasympathetic nervous system, rapidly reducing cortisol.
Yoga and tai chi: regular practice reduces both physical and hormonal stress load.
Time spent in nature: 2 hours of weekly "forest bathing" significantly reduces stress hormones (Japanese Shinrin-yoku studies).
Social connections: loneliness increases chronic stress indicators; strong social networks improve multiple health parameters, including skin.
Previous chapter
Sleep and Circadian Rhythm: The Skin's Repair Window