What Causes Bronchial Asthma? Understanding the Triggers from Eastern and Western Medical Perspectives
The Traditional Chinese Medicine (TCM) View on Asthma Development
According to Traditional Chinese Medicine (TCM), asthma is primarily rooted in the presence of "phlegm lodged in the lungs" (known as "fu tan"), which obstructs the airways, causes bronchial constriction, disrupts normal lung function, and leads to the upward surge of lung Qi—ultimately triggering an asthma episode. This condition is classified as a chronic respiratory disorder involving the lung system, where multiple internal and external factors interact to initiate symptoms.
Environmental and External Triggers
External pathogens such as cold, heat, or dampness can invade the lungs and impair their ability to disperse and descend Qi. When the lung's natural function is compromised, stagnation occurs, leading to blocked airflow. Common environmental irritants like smoke, dust, pollen, and air pollution can further aggravate this imbalance. For instance, exposure to cold may cause fluids to congeal into phlegm, while excessive heat can vaporize body fluids and transform them into sticky mucus. This phlegm then blocks the air passages, restricting breathing and resulting in wheezing and shortness of breath—classic signs of asthma.
Dietary Influences on Respiratory Health
Poor dietary habits play a significant role in the development of asthma from a TCM standpoint. Overconsumption of greasy, sweet, or raw foods—or excessive alcohol intake—can impair spleen function. The spleen, responsible for transforming nutrients and fluid metabolism, becomes weakened and fails to process dampness properly. As a result, internal phlegm forms and rises to affect the lungs, obstructing lung Qi and contributing to recurrent asthma attacks. If this phlegm accumulates over time and combines with internal heat, it creates a condition known as "heat-phlegm," which manifests as more severe, inflammatory-type asthma characterized by yellow sputum, restlessness, and rapid breathing.
Emotional and Psychological Factors
Emotions are deeply connected to organ function in TCM. Chronic stress, anxiety, sadness, or repressed anger can lead to liver Qi stagnation. Since the liver regulates the smooth flow of energy throughout the body, its dysfunction can directly impact the lungs. When liver Qi rebels upward, it interferes with the lung's ability to regulate respiration, causing obstruction and dyspnea. This mind-body connection highlights how emotional well-being is essential in managing and preventing asthma flare-ups.
Chronic Illness and Kidney Deficiency
In long-term asthma cases, the disease often progresses beyond the lungs and affects other organs, particularly the kidneys. Prolonged illness, aging, or excessive physical strain can weaken kidney Qi, impairing its vital role in anchoring and receiving Qi. When kidney function declines, especially the yang aspect responsible for warming and transforming fluids, it can no longer support proper respiration. Fluid retention may occur, leading to water accumulation that overwhelms the heart and lungs—a condition referred to as "water rebellion affecting the heart and lungs." This stage typically presents with severe breathlessness, fatigue, and edema, indicating advanced constitutional weakness.
The Western Medical Perspective on Asthma Etiology
From a modern medical standpoint, bronchial asthma is understood as a complex chronic inflammatory disease of the airways influenced by both genetic predisposition and environmental exposures. It involves hyperresponsiveness of the bronchial tubes, leading to recurring episodes of wheezing, chest tightness, coughing, and difficulty breathing.
Genetic Susceptibility and Family History
Research consistently shows that asthma tends to run in families. Individuals with close relatives—especially parents or siblings—who have asthma are at a significantly higher risk of developing the condition themselves. The closer the genetic relationship, the greater the likelihood of inheritance. Moreover, the severity of asthma in one family member often correlates with increased prevalence among others, suggesting a strong hereditary component involving immune regulation and airway structure.
Allergens and Immune System Activation
Common allergens act as key triggers in sensitized individuals. These include house dust mites, mold spores, animal dander, pollen, and even occupational agents like wood dust or coffee bean particles. Certain medications—such as aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), and beta-blockers like propranolol—can also provoke asthma symptoms in susceptible people. When these substances enter the body, they stimulate an exaggerated immune response, leading to airway inflammation, mucus production, and bronchoconstriction.
Environmental and Lifestyle Triggers
Beyond allergens, numerous environmental and behavioral factors can precipitate asthma attacks. Air pollution, tobacco smoke, and strong chemical fumes are major contributors. Viral infections of the upper respiratory tract—especially in children—are frequent initiators of acute episodes. Other common triggers include intense physical activity (exercise-induced asthma), changes in weather, hormonal fluctuations during pregnancy, and even emotional stress. Interestingly, even inhaling cold, dry air or distilled water vapor can cause airway irritation in sensitive individuals due to heightened bronchial reactivity.
A Multifactorial Condition Requiring Holistic Management
Asthma is not caused by a single factor but emerges from a dynamic interplay between genetics, immunity, environment, and lifestyle. While Western medicine focuses on controlling inflammation with corticosteroids and relieving symptoms with bronchodilators, integrating insights from traditional systems like TCM offers a more comprehensive approach. Addressing root imbalances—whether through diet, emotional health, herbal therapy, or environmental control—can empower patients to reduce reliance on medication and improve long-term outcomes.