The Space Between
Fascia, Lung Qi, and the Psychic Immune System
This essay continues my exploration of the Lungs in Chinese Medicine. In last week’s piece, “The Sixth Sense of the Soulful Animal,” I reflected on the Po—the Corporeal Soul—and interoception as the body’s sixth sense. Here, I turn to another function of the Lungs: the dispersal of Defensive (Wei) Qi through the Cou Li space, the energetic terrain between skin and muscle that protects us from external and internal disruptions alike. Drawing on fascial science, breathwork, and the lived practice of Yin Yoga, this is an inquiry into the body’s subtle immune system—biological, energetic, and psychic—and how our practice can help nourish it.
A little over a week ago, I woke early to a familiar constellation of symptoms: throat on fire, nose congested, body pulsing with strange aches, and a psyche that wanted nothing more than to disappear under the duvet.
It was, of course, just a cold. Or, in the language of Chinese Medicine, a Wind-Cold invasion — an external disruption of the body’s Qi flow by pathogenically “evil” Qi. Not catastrophic, but enough to derail momentum and loosen the stitching of self. As I lay there—body heavy, mind racing—fear, shame, and helplessness unfurled through me.
My physical and psychic immune systems were crashing in unison.
But then I remembered something a student once said in class: Illness is a teacher. Whether minor or massive, every illness rattles the internal thermostat, disrupting the illusion of permanence and control. And, perhaps, returning us to something essential.
So I took a breath. And another.
And another.
Gradually, awareness coalesced. The thoughts unhooked from the tissue. The aches remained, but something inside began to orient again. I tossed back the duvet and said to myself: “Right. Kettle. Neti pot. Scarf around the neck to shield from Evil Pernicious Influences.”
The Lung’s Hidden Terrain
In Traditional Chinese Medicine (TCM), the Lungs are not just pumps of breath. They are the tender organ, responsible for dispersing Qi, regulating water metabolism, and—crucially—governing the skin and the Cou Li, the energetic space between the skin and muscles.
This Cou Li space is where Defensive Qi (Wei Qi) flows. It is the body’s first line of defense against invading pathogens—what ancient texts call Evil Pernicious Influences (EPI): Wind, Cold, Damp, Dryness, and Heat.
From the Nei Jing Su Wen:
“The Lungs are the master of Qi. They regulate the water passages and control the Cou Li. When the Cou Li is open, one sweats; when it is closed, one does not.”
Wei Qi controls the opening and closing of pores. When Lung Qi is strong, the pores open and close appropriately, regulating temperature and preserving internal harmony. When Lung Qi is weak, the pores stay open, making us vulnerable to invasions.
As Maciocia explains:
“The Lungs influence Defensive Qi which flows under the skin... If Lung Qi is weak, Defensive Qi will also be weak and because the pores will be open, the person will be prone to attack by exterior pathogenic factors.”
Fascia: The Biological Cou Li
In modern anatomical terms, we can understand the Cou Li as a superficial layer of fascia. This living matrix beneath the skin is rich with lymph vessels, capillaries, mast cells, and immune surveillance cells. It is not just a mechanical tissue, but a sensory interface—a communicative skin of awareness.
The pores, classically seen as the “doors of Qi,” are more than sweat valves. They are energetic membranes regulating relationship—between our inner world and the world around us.
When this layer is fluid, hydrated, and intelligently responsive, our Defensive Qi moves well. But when it’s dry, disorganized, or densified, the immune flow stagnates.
Exogenous Pathogens, Internal Demons
In Chinese Medicine, colds and flus are caused by “Evil Pernicious Influences” or EPIs—but the ancients also spoke of a more insidious kind of invader: the demons of the mind. Delusion, craving, fear, hatred. These, too, are contagious. These, too, enter when the Cou Li of the psyche is weak.
When Lung Qi is weak—spiritually or emotionally—we lose the inner capacity to defend against these invading stories. The mind fuses with the symptoms. The psychic immune system collapses.
But Yin Yoga offers a holistic remedy.
Yin Yoga: Breath as Shield
In a Yin Yoga pose, you are doing more than stretching tissue:
You breathe through the nose → increasing nitric oxide, which boosts immune function and improves circulation.
You breathe from the belly → activating the diaphragm, which pumps lymph and supports immune function.
You release fascial tension → restoring hydration and improving the flow of interstitial fluids.
You remain still → enhancing interoception, your sixth sense, governed by the Lungs’ Corporeal Soul (Po).
You feel discomfort → training your nervous system to remain steady in the face of challenge, to shift from sympathetic alarm to parasympthetic restoration
You witness the moment → strengthening the psychic Cou Li, the subtle membrane between sensation and story.
In TCM terms, you are dispersing stagnant Qi, strengthening your Wei Qi, and restoring the integrity of the Cou Li space.
In modern terms, you’re optimizing the terrain through which immunity, perception, and emotional discernment flow.
Practice as Medicine
This past week, with my cold flaring and my psychic defenses low, I returned to the simplest of rituals:
Settle into a pose
Breathe gently
Feel the weather inside
Sometimes the body burned. Sometimes it trembled. Sometimes I cried. But each time, I felt a little more here. A little more like a safe harbor in the storm.
And maybe that’s what Wei Qi really is:
The ability to remain with yourself when the wind howls outside. The strength to stay rooted even as the mind clouds over. The practice of remembering that, especially in vulnerability, we can still protect the sacred space of the soul.
Practice With Me
🌿 If you’d like to explore how Yin Yoga collaborates with your subtle energy (Qi) from Chinese Medicine, I welcome you to join the Yin Practice Membership.
You’ll receive weekly live Yin classes on Zoom, access to 100+ recorded sessions, and guided practices to help you meet each moment from scratch.
Your fascia—and your soul—will thank you.
— Josh