Japan’s latest COPD guidance begins with a problem that extends well beyond the country: patients carrying the same diagnosis can have markedly different symptoms, risks and treatment needs.
The Japanese Respiratory Society published the seventh edition of its COPD guidelines in March, four years after its previous update. A translated summary published July 14 in Respiratory Investigation was prepared by Hisatoshi Sugiura of Tohoku University Graduate School of Medicine and respiratory specialists from six other Japanese institutions.
The update arrives amid a persistent diagnosis gap. COPD is estimated to affect 8.6 percent of Japanese adults older than 40, the authors report, yet fewer than one in 10 affected people have received a formal diagnosis. That leaves many patients without treatment while also making accurate assessment especially important when the disease is identified.
The guideline highlights characteristics frequently seen in Japanese practice, including lean body composition, comparatively low exacerbation rates and a high prevalence of patients with features of both asthma and COPD. The larger principle is that COPD should not be treated as one uniform disease.
Body composition is one example. A lean patient who has lost muscle and exercise capacity may require nutritional support and pulmonary rehabilitation alongside inhaled treatment. That plan will differ from care for a patient whose dominant problem is repeated exacerbations, persistent mucus or cardiovascular disease.
The seventh edition also formally incorporates the GOLD etiotype classification, which organizes COPD according to contributing causes and biological pathways rather than assuming that every case follows the traditional smoking-related model. It recognizes mucus plugging detected on CT scans as an independent prognostic factor and adds cellular senescence—the accumulation of aging cells that no longer function normally—to its description of disease mechanisms.
Comorbidity management receives greater prominence as well. The Japanese society identifies cardiovascular risk during and after an exacerbation as a core treatment concern, reflecting evidence that a COPD flare can affect far more than the lungs.
The guideline retains 15 clinical questions from the previous edition and adds seven. New questions address long-term macrolide antibiotics, bronchoscopic lung-volume reduction and the management of exacerbations with bronchodilators, systemic corticosteroids, antibiotics and respiratory support.
It also introduces a recommendation for dupilumab in selected patients who have evidence of type 2 inflammation and frequent exacerbations. That is not a general recommendation for everyone with COPD. It reflects the move toward identifying inflammatory characteristics that may predict whether a particular therapy is appropriate.
This approach broadly aligns with the 2026 report from the Global Initiative for Chronic Obstructive Lung Disease, which organizes initial treatment around symptoms, exacerbation risk and blood eosinophil counts. GOLD no longer treats asthma–COPD overlap as a single disease category, instead emphasizing that the two conditions can coexist and share treatable characteristics.
Spirometry remains essential for confirming persistent airflow obstruction, but a lung-function number does not capture the entire burden of COPD. Frailty, mucus, exercise limitation, sleep, anxiety, cardiovascular risk and the likelihood of another exacerbation can all alter the treatment plan.
That is why the most transferable part of the Japanese update is its method of assessment rather than any one prescription. Medication availability, approval decisions and patterns of disease differ between countries. Patients should follow the guidance applicable where they receive care rather than attempting to translate an overseas treatment algorithm themselves.
The guideline instead offers a useful set of questions for a COPD visit: Is the patient losing muscle or weight? Have exacerbations occurred? Is mucus plugging present? Does asthma coexist? Is cardiovascular risk being addressed? Is breathlessness limiting ordinary activity despite otherwise reassuring spirometry?
Japan’s new guidance makes clear that the COPD label is the beginning of the clinical assessment, not the complete treatment plan. Its next challenge is reaching the large majority of affected people who have not yet been diagnosed—and then ensuring that the care they receive reflects the disease they actually have.
