What Is Bronchial Asthma?
Bronchial asthma is a chronic inflammatory disease of the lower airways, characterized by bronchial hyperresponsiveness and variable, reversible airflow obstruction. It manifests as recurrent episodes of wheezing, dyspnea, chest tightness, and cough.
Asthma affects more than 300 million people worldwide. It is the most common chronic disease of childhood and one of the most frequent causes of hospital admission. Mortality, though declining, remains significant — hundreds of thousands of deaths each year globally.
Asthma is a heterogeneous disease with multiple phenotypes and endotypes. Recognizing this heterogeneity has transformed treatment, enabling personalized approaches with targeted biologic therapies for severe, refractory cases.
Chronic Inflammation
Airway inflammation persists even during symptom-free periods. Continuous anti-inflammatory treatment is essential, not just bronchodilator use.
Reversible Obstruction
Bronchoconstriction reverses spontaneously or with treatment, distinguishing asthma from COPD. Spirometry demonstrates this reversibility.
Heterogeneous Disease
Asthma has multiple phenotypes (allergic, eosinophilic, neutrophilic, exercise-induced), each requiring a specific therapeutic approach.
Pathophysiology
Asthma involves three main pathological processes: chronic airway inflammation, bronchial hyperresponsiveness, and airway remodeling. These processes interact to produce variable airflow obstruction.
In allergic asthma (the most common phenotype), allergen exposure activates the Th2 cascade: eosinophils, mast cells, IgE, and type-2 cytokines (IL-4, IL-5, IL-13). Eosinophils release basic proteins that injure the bronchial epithelium, perpetuating inflammation and hyperreactivity.
Remodeling and Hyperresponsiveness
Airway remodeling is a consequence of untreated chronic inflammation. It includes hypertrophy and hyperplasia of bronchial smooth muscle, subepithelial fibrosis, goblet-cell hyperplasia, and neovascularization. These structural changes lead to progressive, partially irreversible obstruction.
Bronchial hyperresponsiveness means the airways react excessively to stimuli that would be harmless in healthy individuals — cold air, exercise, odors, laughter, weather changes. It is a result of chronic inflammation and remodeling.
Symptoms
Asthma symptoms are typically variable and intermittent, with nocturnal and morning worsening. Symptom variability — both throughout the day and in response to triggers — is a key feature that helps distinguish asthma from other causes of dyspnea.
Symptoms of Bronchial Asthma
- 01
Wheezing (chest whistle)
High-pitched expiratory sound caused by airflow through narrowed airways — the most recognizable symptom of asthma.
- 02
Episodic dyspnea
Variable shortness of breath, triggered by exercise, allergens, viral infections, cold air, or emotions. Worsens at night and in the morning.
- 03
Chest tightness
A squeezing or weight on the chest, often described as a belt tightening around the thorax.
- 04
Chronic or recurrent cough
May be the only symptom of asthma (cough-variant asthma). Typically dry, nocturnal, or exercise-induced.
- 05
Nocturnal symptoms
Waking at night with cough, wheezing, or shortness of breath signals uncontrolled asthma.
- 06
Seasonal or perennial symptoms
In allergic asthma, symptoms can be seasonal (pollens) or perennial (mites, fungi).
Diagnosis
Asthma diagnosis is based on a history of variable respiratory symptoms combined with objective demonstration of reversible obstruction on spirometry. Spirometry with a bronchodilator response test (FEV1 increase ≥ 12% and ≥ 200 mL after bronchodilator) confirms the diagnosis.
When spirometry is normal, a methacholine bronchoprovocation test can demonstrate bronchial hyperresponsiveness. Measurement of fractional exhaled nitric oxide (FeNO) helps identify the eosinophilic phenotype and monitor adherence to inhaled corticosteroids.
🏥Diagnostic Confirmation of Asthma
- 1.History of variable respiratory symptoms (wheezing, dyspnea, cough, chest tightness)
- 2.Variable, expiratory airflow limitation documented on spirometry
- 3.Positive bronchodilator response: FEV1 increase ≥ 12% and ≥ 200 mL
- 4.Or PEF variability > 10% in adults on serial measurements
- 5.Or positive bronchoprovocation test (FEV1 drop ≥ 20% with methacholine)
DIAGNÓSTICO DIFERENCIAL
Differential Diagnosis
COPD
Heavy smoking history, irreversible post-bronchodilator obstruction (persistent FEV1/FVC < 0.7), no significant reversibility
Heart Failure
Dyspnea with orthopnea and paroxysmal nocturnal dyspnea, basal crackles, elevated BNP, cardiomegaly on radiography
Bronchiectasis
History of recurrent respiratory infections, chronic purulent expectoration, chest CT showing irreversible bronchial dilation
Vocal Cord Dysfunction
Predominantly inspiratory stridor (not expiratory), young female, rapid resolution, flattened inspiratory loop on spirometry
Gastroesophageal Reflux
Dry nocturnal cough without wheezing, worsens when lying down, heartburn, pyrosis; can coexist with asthma and worsen control
Asthma versus COPD — and the ACO Overlap
Distinguishing asthma from COPD is fundamental to correct treatment. Asthma typically begins in childhood or adolescence, with reversible obstruction, eosinophilic inflammation, and a good response to inhaled corticosteroids. COPD occurs in adults with a heavy smoking history, with irreversible post-bronchodilator obstruction (persistent FEV1/FVC below 0.7) and predominantly neutrophilic inflammation.
Asthma-COPD overlap (ACO) is recognized in up to 20% of patients with obstructive disease, especially older adults and smokers with asthma. These patients carry features of both diseases, suffer more exacerbations, and have a worse prognosis. Treatment combines inhaled corticosteroids (the foundation of asthma care) with long-acting bronchodilators (the foundation of COPD care), under strict monitoring.
Heart Failure — The Diagnosis That Cannot Be Missed
Heart failure can cause dyspnea and wheezing (cardiac asthma), especially in older adults, and may be mistaken for bronchial asthma. Signs that favor CHF include: orthopnea (inability to lie flat), paroxysmal nocturnal dyspnea, lower-limb edema, bilateral basal crackles, jugular venous distension, and hepatomegaly. Elevated BNP or NT-proBNP, cardiomegaly on radiography, and diastolic or systolic dysfunction on echocardiogram confirm the diagnosis.
A diuretic can completely resolve CHF wheezing, whereas asthma does not respond to that treatment. In older patients with new dyspnea, especially those with cardiovascular risk factors, always consider CHF in the differential before assuming asthma. The two diagnoses can coexist, requiring treatment of both.
Vocal Cord Dysfunction
Vocal cord dysfunction (VCD), or paradoxical vocal fold movement syndrome, is often misdiagnosed as refractory asthma. It involves paradoxical adduction of the vocal cords on inspiration, causing inspiratory stridor and episodic dyspnea. VCD mainly affects young women and can be triggered by emotional stress, exercise, or inhaled irritants.
The key clinical difference: in VCD, stridor is predominantly inspiratory (cervical), whereas in asthma it is expiratory (thoracic). Spirometry shows a flattened or truncated inspiratory loop. Laryngoscopy during an episode confirms the diagnosis. VCD does not respond to bronchodilators and requires speech therapy with specific vocal exercises, always coordinated by the physician.
Treatment
Asthma treatment is stepped (GINA steps 1–5), aiming to achieve and maintain disease control. The cornerstone of treatment is the inhaled corticosteroid (ICS), which acts on the underlying inflammation. The long-acting bronchodilator (LABA) is added starting at step 3.
Steps 1-2: Mild Asthma
Low-dose ICS regularly, or ICS+formoterol as needed. GINA 2024 no longer recommends SABA alone without ICS. Using a rescue bronchodilator alone, without an anti-inflammatory, raises the risk of severe exacerbations.
Steps 3-4: Moderate Asthma
Medium- to high-dose ICS combined with LABA (formoterol or salmeterol). Leukotriene receptor antagonists as adjuvants. Tiotropium (long-acting anticholinergic) as an additional option at step 4.
Step 5: Severe Asthma
High-dose ICS + LABA + tiotropium. Phenotyping guides biologic selection: omalizumab (anti-IgE), mepolizumab/benralizumab (anti-IL-5), dupilumab (anti-IL-4/IL-13), tezepelumab (anti-TSLP). Chronic oral corticosteroids only as a last resort.
Complementary Approaches
Patient education and a written action plan, proper inhaler technique, environmental control, treatment of associated rhinitis, smoking cessation, weight management, regular physical activity, acupuncture as an adjunct.
Acupuncture as Treatment
Acupuncture has been investigated as a complementary therapy for asthma. Proposed mechanisms — primarily supported by preclinical studies — include possible modulation of bronchial inflammation (Th2 cytokine and eosinophil parameters), effects on the autonomic nervous system that could favor bronchodilation, and modulation of bronchial hyperreactivity and the immune response. Consistent clinical translation of these findings has not yet been established.
Experimental studies show that acupuncture can reduce eosinophilic airway inflammation and bronchial hyperresponsiveness in animal models of asthma. Clinical studies show improved quality of life and reduced symptoms, although the effect on pulmonary function is less consistent.
Acupuncture does not replace standard pharmacological treatment of asthma. It may be considered as an adjunct, especially for patients with mild to moderate asthma who want a complementary approach. A typical protocol runs 10–12 sessions over 8–12 weeks.
Prognosis
With adequate treatment, most people with asthma can achieve complete symptom control and a normal life, with no limitations. Prognosis depends on severity, treatment adherence, and control of triggering factors.
Childhood-onset asthma may go into remission in adolescence in up to 50% of cases, although it can recur in adulthood. Late-onset asthma (after age 40) tends to be more persistent and less responsive to treatment.
Bronchial remodeling driven by years of uncontrolled inflammation can lead to partially fixed obstruction, similar to COPD. Early, consistent ICS treatment prevents this unfavorable course.
Myths and Facts
Myth vs. Fact
Asthma inhalers are addictive or harm the heart
Inhaled corticosteroids are not addictive and have minimal systemic effects. Bronchodilators can cause transient tremor and tachycardia but are safe at recommended doses.
Asthmatics should not exercise
Regular physical activity is recommended for people with asthma — it improves cardiorespiratory fitness and disease control. Exercise-induced bronchoconstriction can be prevented with a bronchodilator before activity.
Asthma is cured — just stop the medication when you feel better
Asthma is a chronic disease. Symptom improvement with treatment reflects control, not cure. Premature discontinuation of ICS leads to return of inflammation and symptoms.
I only need medication when I have symptoms
Bronchial inflammation persists even without symptoms. Daily maintenance ICS prevents exacerbations and remodeling. Relying on a rescue bronchodilator alone is insufficient and dangerous.
Asthma is an emotional or psychological disease
Asthma is an inflammatory disease with a well-defined immunological basis. Although emotional stress can trigger attacks, the cause is chronic airway inflammation, not psychological factors.
When to Seek Care
Asthma requires regular medical follow-up. Some situations call for urgent evaluation.
Frequently Asked Questions
Asthma has no definitive cure, but it can be fully controlled. With proper treatment — maintenance inhaled corticosteroids plus trigger control — most people with asthma lead a normal life with no symptoms or limitations. Control is not cure, but in daily life it is indistinguishable from it.
Asthma typically begins in childhood with reversible obstruction, eosinophilic inflammation, and a strong atopic component. COPD occurs in adults with a heavy smoking history and produces irreversible, progressive obstruction. The two can coexist (ACO — asthma-COPD overlap), especially in older smokers with asthma.
Medical acupuncture has been studied as an adjunct. Its proposed mechanisms — modulating bronchial inflammation (Th2 cytokines, eosinophils), autonomic tone, and airway hyperreactivity — rest mainly on preclinical evidence. Clinical trials suggest a potential benefit for quality of life, while effects on exacerbation frequency and pulmonary function are less consistent. It never replaces inhaled corticosteroids, which remain the foundation of treatment.
Yes — and they should. Physical activity is recommended for people with controlled asthma. To prevent exercise-induced asthma, the physician may recommend a short-acting bronchodilator (albuterol) before activity. Aquatic sports are often better tolerated thanks to the warm, humid air.
These are monoclonal antibodies that block specific cytokines or receptors in the asthmatic inflammatory cascade. They include omalizumab (anti-IgE), mepolizumab and benralizumab (anti-IL-5), and dupilumab (anti-IL-4/IL-13). They are indicated for severe eosinophilic asthma uncontrolled on optimized conventional treatment, and they dramatically reduce exacerbations.
Fractional exhaled nitric oxide (FeNO) is a biomarker of eosinophilic airway inflammation. Elevated values (above 50 ppb) suggest eosinophilic asthma with a high probability of response to inhaled corticosteroids. FeNO is also useful for monitoring treatment adherence and adjusting doses.
Yes, very strongly. The "unified airway" concept recognizes that rhinitis and asthma are manifestations of the same inflammatory process at different levels of the airway. Up to 80% of asthmatics have concomitant rhinitis, and uncontrolled rhinitis worsens asthma control. Adequately treating rhinitis frequently also improves asthma control.
At low to moderate doses, yes. The systemically available dose is minimal (less than 10–20% of the inhaled dose). Risks include oral candidiasis (prevented by rinsing the mouth with water after use) and, rarely, reduced bone density with very high doses over many years. The risks of uncontrolled asthma far outweigh those of ICS.
Severe attack: intense dyspnea that prevents speaking full sentences, no response to the bronchodilator, cyanosis (blue lips), saturation below 92%, mental confusion, or drowsiness. In these cases, seek emergency care immediately. While waiting for help, use the rescue bronchodilator and sit upright to ease breathing.
Typical asthma protocols consist of 10–12 sessions in an initial cycle (twice weekly), followed by monthly maintenance. Response varies from person to person — many patients notice improvement within the first sessions. The medical acupuncturist will design a personalized plan, tailored to severity and clinical response.
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