# Why Do the Chinese Say "The Lung Governs the Skin and Hair"? Your Lung Is Not Just a Respirator, but an Air Purifier + Air Conditioner
A Question
Have you ever had this experience?
As soon as autumn arrives, your skin starts to "protest." White scales appear on your calves, like a layer of powdered milk; your lips crack, and lip balm still leaves them peeling; your face feels tight, and a face mask only helps for two hours. You buy more expensive face creams, switching from lotion to essence oil—nothing works. Traditional Chinese Medicine (TCM) says: "The lung governs the skin and hair; when the lung is dry, the skin becomes dry."
Your colleague wears a short-sleeve shirt, while you still feel cold in two layers. A blast of air conditioning in the office makes you sneeze and have a runny nose, and the next day you catch a cold. You get colds five or six times a year, and while others recover in three days, it takes you two weeks. You think it's a "weak constitution," so you take vitamin C, zinc, and probiotics, but the effects are limited. TCM says: "Lung qi is weak, and the protective barrier is not solid."
You have a breakup, or a loved one passes away. You sit on the sofa, not crying, but your chest feels like a stone is pressing on it. Your breathing becomes shallow, as if someone has compressed your lungs by half. You take a deep breath, but your chest still feels tight. TCM says: "Grief harms the lung."
You go to the hospital, get a chest X-ray, lung function test, allergy test, and immunoglobulin test. The doctor says: "Everything is normal; you might just have a sensitive constitution."
You go to a TCM practitioner. The old doctor listens to your breathing (a bit shallow and rapid), looks at your tongue (reddish at the front, with little coating), and says: "Lung qi deficiency, insufficient body fluids."
How can one organ—the lung—govern the skin, colds, and sadness?
Even more surprisingly, TCM says the lung is the "minister"—the prime minister who assists the ruler. Who does the lung assist? It assists the heart. The heart governs the blood, and the lung governs the qi; qi and blood are interdependent, and the heart and lung are one family. This network of relationships is more complex than a palace drama.
Traditional Chinese Explanation
The character "肺" (lung) in the Shuowen Jiezi is described as "the metal organ"—it belongs to the metal element, corresponds to autumn, and represents the energy of contraction. The ancients observed that in autumn, all things contract, leaves wither, the air becomes dry, and people are prone to dry skin, coughing, and low mood. They associated these phenomena with the "lung."
TCM's understanding of the "lung" is like a sophisticated air processing system with five core functions:
First: The lung governs qi and controls respiration. This is the most well-known function. The lung inhales clear qi from nature (oxygen) and exhales turbid qi from the body (carbon dioxide), while simultaneously promoting the movement of qi throughout the body. When lung qi is abundant, your breathing is deep, your voice is strong, and your energy is plentiful. When lung qi is deficient, your breathing is shallow and short, your speech is weak, and you tire easily.
Second: The lung governs diffusion and descent. "Diffusion" (宣發) means dispersing upward and outward—transporting qi and body fluids to the whole body, especially the skin and pores. "Descent" (肅降) means clearing downward and inward—transporting metabolic waste gases and fluids downward, ultimately to be excreted through the kidneys and bladder. Poor diffusion means the skin lacks nourishment, becoming dry and dull; poor descent means fluid metabolism is impaired, leading to phlegm, edema, and chest tightness.
Third: The lung governs the skin and hair, and opens into the nose. The essence of the lung is transported to the skin and pores through its diffusion function. When lung qi is abundant, the skin is moist, the pores open and close properly, and immunity is strong. When lung qi is deficient, the skin becomes dry, the pores open and close abnormally, and you are prone to catching colds. The nose is the "gateway" of the lung—when lung qi is deficient, you experience nasal congestion, runny nose, and reduced sense of smell.
Fourth: The lung governs the regulation of water passages. The lung participates in the body's fluid metabolism. It transports "water" downward, to be excreted through the kidneys and bladder. If the lung's descent function is impaired, fluids accumulate, forming phlegm, edema, and pleural effusion. TCM says: "The spleen is the source of phlegm production, and the lung is the container of phlegm"—the spleen produces phlegm, and the lung stores it.
Fifth: The lung's emotion is grief. TCM believes that the five organs correspond to five emotions: heart-joy, liver-anger, spleen-overthinking, lung-grief, and kidney-fear. Excessive grief consumes lung qi—"grief dissipates qi." When you cry for a long time, you feel tired—not because your eyes are tired, but because your lung qi has been "cried out."
The lung's relationship with other organs:
Lung and Heart: The heart and lung reside together in the upper burner (上焦), and qi and blood are interdependent. The heart governs the blood, and the lung governs the qi; when qi moves, blood moves, and when blood arrives, qi arrives. If lung qi is deficient, the heart cannot get enough oxygen, leading to palpitations and shortness of breath.
Lung and Spleen: The spleen is the mother of the lung. The spleen transforms and transports the essence of food and water upward to the lung, so the lung can generate "ancestral qi" (宗氣). People with spleen deficiency are also prone to lung qi deficiency, manifesting as frequent colds, shortness of breath, and a low voice.
Lung and Kidney: The lung is the upper source of the kidney. The lung controls exhalation, and the kidney controls the reception of qi. The lung draws qi in, and the kidney "holds" it. If the kidney fails to receive qi, a person will wheeze—able to inhale but not exhale, with qi floating in the chest.
The ancients likened the lung to the prime minister (相傅). The prime minister does not rule the country, but he regulates the rise and fall of qi throughout the nation. If the prime minister falls, the qi of the entire country is in chaos.
Alright, now let's translate "lung" into modern terms.
I'm not going to talk about alveolar surface area, surfactant, or ventilation-perfusion ratio. Too complicated. You just need to remember one metaphor:
Air Purifier Part: This is the lung function well-known to modern medicine. With each breath, about 500ml of air enters the alveoli. The alveolar wall is as thin as a hair (about 0.5 microns); oxygen diffuses into the blood, and carbon dioxide diffuses from the blood into the alveoli to be exhaled. About 15,000 liters of air pass through the lungs every day, and the total alveolar surface area is about 70-100 square meters—larger than a tennis court.
Air Conditioning System Part: This is the modern equivalent of "the lung governs the skin and hair."
Skin and Lung: The skin is the largest organ of the human body, covering about 1.5-2 square meters. Healthy skin needs adequate oxygen, water, and nutrients. The oxygen inhaled by the lungs is transported to the skin through the blood; the carbon dioxide exhaled by the lungs is carried away from the skin through the blood. Poor lung function means insufficient oxygen supply to the skin, metabolic waste accumulates, and the skin becomes dry, dull, and prone to aging. TCM's "the lung governs the skin and hair" corresponds in modern physiology to the "lung-blood-skin" oxygen and nutrient supply chain.
Pores and Immunity: Pores (sweat gland openings) are not only heat dissipation channels but also part of the immune defense line. The skin surface has symbiotic flora that secrete antimicrobial peptides, forming a "chemical barrier." When lung qi is abundant (good immunity), the skin flora is balanced, the pores open and close properly, and external pathogens find it difficult to invade. When lung qi is deficient (low immunity), the skin barrier is damaged, and pathogens can easily "break in" through the pores—this is the microscopic mechanism of "easily catching colds."
Fluid Regulation and Lung: The lung's participation in the body's fluid metabolism corresponds to the regulation of "antidiuretic hormone (ADH)" secreted by the lung and the lung's perception of plasma osmotic pressure. At the same time, about 300-400ml of water is evaporated through the respiratory tract every day during breathing (insensible water loss). Abnormal lung function leads to abnormal water evaporation from the respiratory tract, exacerbating dry skin. "Lung dryness" corresponds to the imbalance of water evaporation in the respiratory tract and skin.
Grief and Lung: Grief activates the amygdala and prefrontal cortex of the brain, affecting the respiratory rhythm through the vagus nerve. In grief, people tend to breathe shallowly and rapidly (sighing breathing), leading to insufficient alveolar ventilation, a slight drop in blood oxygen partial pressure, and the subjective feeling of "chest tightness." Long-term grief or depression leads to chronic low-grade hypoxia, which reduces immune function and makes one more susceptible to respiratory infections. TCM's "grief harms the lung" corresponds to the vicious cycle of emotion-breathing-immunity.
Nose and Lung: The nasal mucosa is the first line of defense of the respiratory system, filtering, warming, and humidifying the air. The cilia movement and mucus secretion of the nasal mucosa directly "sweep" pathogens to the pharynx to be swallowed (about 1 liter of mucus per day). When lung qi is deficient (low immune function), the barrier function of the nasal mucosa is weakened, making one prone to rhinitis, allergies, and colds. TCM's "the lung opens into the nose" corresponds to the immune function of the nasal mucosa as the gateway of the respiratory tract.
So, "the lung governs the skin and hair" is not metaphysics. It is a functional metaphor—describing the lung's role as an "air processor and climate regulator" in the network of respiration, skin, immunity, and emotional regulation. The lung is not just a respirator; it is also the "atmosphere" of your body.
Life Cases
Four stories to help you instantly understand what the "lung" really is.
Case One: Skin Cracks in Autumn, Face Cream Doesn't Help.
Ms. Chen, 35, every autumn, her calves start to "snow"—white scales flying everywhere. She has tried five different body lotions, from budget to luxury brands, but they only help for a few hours. Her lips are so cracked she can't even apply lipstick. TCM says: "Lung dryness and fluid deficiency, the skin and hair lose nourishment."
The truth: In autumn, air humidity drops, and water evaporation from the respiratory tract accelerates. At the same time, skin sebum secretion decreases, and water loss from the stratum corneum accelerates. When lung function is normal, the skin receives sufficient water and oxygen through blood circulation to compensate for the dry environment. But for people with insufficient lung qi or fluid deficiency, the skin's "supply chain" is broken, and internal hydration is insufficient. No matter how much face cream you apply externally, it's just a "surface job." It's like a dry room with air conditioning: you can either turn on a humidifier (replenish fluids from the inside) or apply moisturizer (surface hydration). Only doing the latter treats the symptom, not the root cause.
Case Two: Catch a Cold with Every Blast of Air Conditioning, Six Times a Year.
Xiao Li, 28, an office clerk. In summer, as soon as the air conditioning blows, she is the first to sneeze. During seasonal transitions in spring and autumn, she always catches a cold. She never misses a flu outbreak. Her physical exam is normal, but her immunity is like paper. TCM says: "Lung qi deficiency, the protective barrier is not solid."
The truth: The respiratory mucosa is the first line of defense of the human immune system. In healthy people, the nasal and tracheal mucosa secrete IgA (immunoglobulin A), forming an "antibody coating." People with lung qi deficiency (low immune function) have reduced mucosal IgA secretion and decreased cilia clearance ability, making it easier for pathogens to attach and invade. At the same time, their body temperature regulation is poor, and their pores open and close abnormally—dissipating heat when they should, but staying open when they should retain warmth. Catching a cold six times a year is not "bad luck"; it's a "hole in the atmosphere."
Case Three: Chest Tightness and Shallow Breathing During Grief.
Lao Zhang, 55, three months after his mother's death, has been feeling chest tightness, as if a stone is pressing on it. His breathing has become shallow, and the number of sighs has increased significantly. He thought something was wrong with his heart, but his ECG and cardiac enzymes were normal. TCM says: "Grief harms the lung, lung qi is dissipated."
The truth: Grief activates the amygdala and limbic system of the brain, inhibiting the activity of the diaphragm and intercostal muscles through the vagus nerve, leading to shallow breathing and a slower frequency. Alveolar ventilation decreases, and blood oxygen saturation slightly drops (possibly from 98% to 95%), producing a feeling of chest tightness and fatigue. In a state of long-term grief, chronic low-grade hypoxia inhibits immune cell activity, and cortisol levels rise, further weakening immunity. TCM's "grief dissipates qi" is, in modern physiology, a chain reaction of "emotional breathing suppression + chronic hypoxia + immune suppression."
Case Four: Allergic Rhinitis, Flares Up Every Spring and Autumn.
Mr. Wang, 30, every spring and autumn, sneezes until his abdominal muscles ache, his nose runs like a tap, and his eyes itch as if sand has gotten in them. He takes antihistamines, which help a bit, but they make him drowsy and dry-mouthed. TCM says: "Lung qi deficiency, the nasal orifices are not functioning well."
The truth: Allergic rhinitis is an overreaction of the immune system to harmless substances like pollen and dust mites. The Th2-type immune response dominates, a large amount of IgE antibodies are produced, mast cells degranulate, and histamine is released. People with lung qi deficiency (immune dysregulation) have a weak respiratory mucosal barrier, making it easier for antigens to enter, and the immune system "misjudges" the threat level. Antihistamines block the symptoms but do not repair the mucosal barrier. TCM's "tonifying lung qi" corresponds to enhancing mucosal immunity and regulating the Th1/Th2 balance to reduce allergic reactions from the source.
Modern Research
Is there a scientific basis for "the lung governs the skin and hair"?
Yes, and it's very direct. Scientists don't use the term "skin and hair"; they use:
• Skin-Lung Axis. A 2019 study published in the Journal of Allergy and Clinical Immunology found that impaired skin barrier function (such as eczema and dry skin) increases the risk of respiratory allergies and asthma. The skin and lungs share multiple immune mechanisms, such as antigen presentation by Langerhans cells and dendritic cells. TCM's "the lung governs the skin and hair" has found a clear anatomical and physiological basis in modern immunology.
• Respiratory Flora and Skin. The microbial composition of the nasal cavity and respiratory mucosa is significantly correlated with the skin flora. After lung infections (such as pneumonia), patients often develop skin lesions (such as erythema nodosum). The lung-skin-microbe network is becoming a new research hotspot.
• Brain Mechanisms of Emotion and Breathing. A 2018 study by Harvard Medical School found that slow, deep breathing (6 times per minute) can activate the prefrontal cortex, inhibit amygdala activity, and significantly reduce anxiety levels. This is completely consistent with the TCM practice of "regulating breathing to nourish the lung." When you are sad, your breathing becomes shallow; deep breathing can relieve chest tightness—it's not a psychological effect, but a neurophysiological mechanism.
These studies fully demonstrate that "the lung governs the skin and hair" is a phenomenon that can be precisely described in modern scientific language. The ancients summarized it with "skin and hair," while modern people describe it with "skin-lung axis," "mucosal immunity," and "respiratory flora"—they are talking about the same thing.
Practical Methods
Now that you understand the "lung," how do you take care of it?
First, let's debunk a few myths:
• Moistening the lung means drinking more water. Wrong. Simply drinking more water, if the spleen and stomach's transformation and transportation ability is poor, the water cannot be converted into "body fluids" and instead becomes "dampness"—leading to edema and excessive phlegm. The key to moistening the lung is "generating fluids," not "flooding with water." The "moistening" effect of foods like pears, white fungus, lily bulbs, and Ophiopogon japonicus lies in their nutritional components (polysaccharides, mucilage) that can protect and repair the respiratory mucosa, while also promoting saliva and mucus secretion.
• Take antibiotics as soon as you catch a cold. Wrong. 80% of colds are caused by viruses, and antibiotics are ineffective against viruses. They also destroy the respiratory and intestinal flora, reducing mucosal immunity. In the early stages of a cold, rest, drinking more water, and keeping the air humid are more important than antibiotics. TCM's "supporting the righteous to expel the evil" corresponds to strengthening immunity and letting the immune system clear the virus on its own.
Specific Methods:
• Abdominal breathing, 10 minutes a day. Inhale with the abdomen bulging, exhale with the abdomen contracting. 6-8 times per minute, slow and deep. Abdominal breathing increases alveolar ventilation, activates the parasympathetic nervous system, and reduces anxiety levels. At the same time, deep breathing massages the internal organs and promotes lymphatic return. TCM's "regulating breathing" is called "respiratory training" in modern medicine—used clinically as an adjunctive treatment for asthma, anxiety, and high blood pressure.
• Eat white foods in autumn. White fungus, lily bulbs, pears, Chinese yam, and white radish. TCM says "white enters the lung." Modern nutrition has confirmed that these foods are rich in polysaccharides, mucilage, and vitamin C, which can protect the respiratory mucosa, promote mucus secretion, and relieve dryness. Tremella polysaccharides have been proven to have immune-modulating effects. It's not a miracle drug, but eating them 2-3 times a week in autumn is like changing the filter of your "air purifier."
• Protect the neck and back, avoid direct cold wind. The Feishu (Lung Shu) point is located 1.5 inches lateral to the spinous process of the third thoracic vertebra on the back; it is where lung qi is transported to the body surface. Direct cold wind on the neck and back causes the pores to close suddenly, obstructing the diffusion of lung qi, and making one prone to catching a cold. Wearing a thin scarf in an air-conditioned room in summer and a scarf in autumn and winter is not about being "afraid of the cold," but about protecting the "lung qi outlet."
• Swimming. Swimming is the only exercise that makes the lungs work under "pressure." Water pressure compresses the chest cavity, increasing respiratory resistance, and the alveoli need to expand more forcefully. Long-term swimmers have significantly increased lung capacity and stronger respiratory muscles. At the same time, the aquatic environment reduces joint pressure, making it suitable for all ages. Note: Pool chlorine may irritate the respiratory tract; choose a well-ventilated pool, and rinse your mouth and nasal cavity after swimming.
• Maintain indoor humidity at 40-60%. Dry air accelerates water evaporation from the respiratory mucosa, destroying the mucus barrier and making it easier for pathogens to attach. A humidifier is not about being "delicate"; it's about maintaining the normal operation of the "air purifier." Note: Change the water in the humidifier daily and clean it weekly to avoid the growth of bacteria and mold—otherwise, the humidifier becomes a "bacterial sprayer," which is counterproductive.
You don't need to believe in TCM to use these methods. You just need to understand: your lungs are not just two air sacs; they are the "atmosphere" of your body—filtering air, regulating humidity, defending immunity, and influencing emotions. When the atmosphere has a problem, it's not just difficulty breathing; the whole body is affected.
One-Minute Summary
🕐 Understand the "Lung" in One Minute
Lung = Air Purifier + Air Conditioning System.
Lung governs qi = Inhale oxygen, exhale waste gas.
Lung governs diffusion and descent = Transport fluids to the skin, and send waste water downward.
Lung governs the skin and hair = Whether the skin is good or not depends on whether the lung is moist.
Lung's emotion is grief = Breathing becomes shallow when sad, consuming lung qi.
Dry skin, frequent colds, chest tightness and sighing, allergic rhinitis—all are holes in the atmosphere.
Causes: Dry environment, direct cold wind, emotional suppression, smoking, air pollution.
Methods: Abdominal breathing, white foods, protecting the neck and back, swimming, maintaining indoor humidity.
The ancients called it "the lung governs the skin and hair"; modern people call it "skin-lung axis," "mucosal immunity," and "respiratory flora."
The names are different, but the body knows: the lung is not just a respirator; it is the atmosphere of your entire body.
xiaokz · Concept 24
Using the language of modern science to help the world understand traditional Chinese wisdom.
Not mysterious, not superstitious, not disparaging.
Understanding, not just believing.