Professor Felix Herth, M.D., is one of Germany’s leading experts in the field of pulmonology and respiratory medicine. As chief physician of the relevant department at the Thoraxklinik Heidelberg and, concurrently, the facility’s medical director, he plays a key role in shaping the direction and further development of this long-established and highly specialized clinic. His many years of experience and scientific expertise make him a key figure in modern pulmonary medicine, particularly in the areas of obstructive airway diseases, noninvasive ventilation, and the specialized diagnosis of complex pulmonary conditions.
The Thoraxklinik itself is one of Europe’s oldest and most renowned specialized clinics for chest diseases. Today, it offers a comprehensive range of medical services, ranging from medical oncology to pulmonology and sleep medicine, as well as radiology, pain management, and allergology. The clinic is particularly distinguished by its close interdisciplinary collaboration. The Department of Pulmonology and Respiratory Medicine works hand in hand with thoracic surgery, thoracic oncology, anesthesiology, and radiology—a collaboration that is highly attractive to both patients and specialists. A particular focus is placed on the specialized care of patients with chronic lung diseases such as COPD, pulmonary emphysema, or pulmonary hypertension, as well as sleep-related breathing disorders.
Patients with rare lung diseases or complex infections, such as tuberculosis, also find specialized treatment options here. The integrated lung cancer center works closely with the departments of thoracic surgery and oncology to ensure guideline-based and individually tailored therapy for patients with malignant lung diseases. Under the leadership of Prof. Dr. Herth, the clinic not only plays a central role in patient care but is also actively engaged in clinical research. New therapeutic approaches are continuously tested in controlled studies and integrated into daily clinical practice. The department maintains a broad international scientific network—particularly in the areas of COPD, endoscopy, pulmonary fibrosis, and pulmonary hypertension—and thus contributes significantly to the advancement of pulmonary medicine.
The editorial team of the Leading Medicine Guide spoke with Prof. Dr. Herth and learned more about the lung disease COPD.
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Chronic obstructive pulmonary disease (COPD) is a widespread, progressive respiratory disease characterized primarily by a persistent narrowing of the bronchi. In most cases, long-term exposure to harmful substances, particularly through tobacco smoking, is the primary cause. COPD is one of the leading causes of illness and death worldwide. Since it is incurable but well-managed, early diagnosis and personalized treatment play a crucial role in the course of the disease and the quality of life of those affected.
COPD is a chronic lung disease that clinically encompasses the components of chronic bronchitis and pulmonary emphysema. It is characterized by progressive airflow limitation, which is generally not fully reversible.
“COPD is a disease that poses difficulties even in terms of terminology, because we don’t have a truly appropriate German term for it. The most common term is the abbreviation COPD, which stands for ‘Chronic Obstructive Pulmonary Disease’—and that already covers the essentials: chronic, obstructive, and affecting the lungs. Chronic means that it is an incurable disease. Obstructive means that the airways are narrowed. As a result, patients experience the three classic main symptoms: shortness of breath, cough, and phlegm. These symptoms can occur individually or in combination. The narrowing of the airways causes less air to pass through, similar to a traffic jam on the highway. The lungs often respond to this restriction by producing more mucus, which in turn leads to coughing in order to expel the mucus. Smoking is considered the primary cause, with both active and passive exposure playing a role. In Germany, COPD is primarily found among smokers, whereas in other countries, open fires used for cooking play a major role. Long-term exposure to air pollution from fine particulate matter can also contribute to the development of COPD. In addition, there is a rare genetic variant of the disease, known as alpha-1 antitrypsin deficiency, which can be diagnosed through a blood test,” explains Prof. Dr. Herth at the beginning of our conversation, elaborating on the chronic nature of the disease:
“The disease is chronic from the very beginning, as soon as it is present. The real problem is that patients often don’t notice the impairment until very late. To illustrate this, I often ask a practical question: What percentage of lung capacity is actually used when sitting in a relaxed position? Many people initially think it’s a high percentage, but in fact, at rest, we only need about five percent of our lung capacity. During power walking or similar physical exertion, about fifty percent is required. This is precisely why many people affected don’t notice anything until fifty percent of their lung capacity has already been permanently damaged—damage that cannot be reversed. It usually takes twenty to thirty years for the disease to become clearly noticeable, which is why COPD is often not diagnosed until people are in their fifties or sixties.
Patients eventually come to the doctor’s office for various reasons: Some suffer from a persistent cough, others notice increased phlegm, or experience shortness of breath, such as when climbing stairs. One of these symptoms is always the primary concern. The diagnosis itself is relatively straightforward and is made using a lung function test. This test measures deviations from normal values, which are determined by age, gender, height, and weight. Although the lung function test is covered by health insurance, it is not offered as frequently in medical practices as, for example, an ECG, since it requires active participation from the patient and is more time-consuming to perform. Nevertheless, any patient can request such a test as part of a check-up. After diagnosis, the disease is further classified based on the extent of lung function impairment and the patient’s symptoms. Special symptom questionnaires are used for this purpose, which are used to classify patients into groups A, B, C, or D, supplemented by a number to accurately assess the severity of COPD.”
The treatment of chronic obstructive pulmonary disease (COPD) aims to alleviate symptoms, improve quality of life, slow the progression of the disease, and prevent exacerbations or reduce their severity.
Prof. Dr. Herth explains: “Treatment options for COPD always begin with eliminating potential harmful influences, known as noxious agents. So if a patient smokes, the first step is to get them to quit smoking. First, we check whether such a noxious agent is present. Physical activity is extremely important for the lungs—as it is for all organs. That’s why there are pulmonary exercise groups that function similarly to cardiac rehabilitation groups, and patients also have the option of participating in a rehabilitation program. In addition, patients are strongly advised to get vaccinated. COPD patients should be vaccinated against the flu, COVID-19, and pneumococcal disease, because any infection can worsen lung function—and that is, of course, something we want to avoid. Once all these non-pharmacological measures have been exhausted, treatment moves on to medications, particularly inhalers. The lungs have a major advantage here: “I can spray the medication directly into the lungs, achieving significant effects with relatively small doses while causing very few systemic side effects.”
Distinguishing between asthma, COPD, and the so-called asthma-COPD overlap (ACO) poses a significant diagnostic challenge in clinical practice, particularly in patients with unclear symptoms or atypical disease progression. A reliable distinction is essential, as the pathophysiological mechanisms—and thus the therapeutic strategies—differ significantly.
Asthma is typically characterized by variable, reversible airway obstruction and marked bronchial hyperreactivity, often accompanied by an allergic diathesis and onset in childhood or adolescence. In contrast, COPD involves progressive, largely irreversible obstruction that typically occurs in older age. “To distinguish between COPD and asthma—which is sometimes not entirely straightforward—imaging is an option, particularly with specialized low-dose CT scans. These allow us to visualize changes in the lungs that are characteristic of one condition or the other. Without this imaging, the distinction is difficult, which is why it frequently happens that patients are treated incorrectly—either a COPD patient receives asthma treatment, or an asthma patient is treated as if they had COPD. “However, because the treatment differs, it is important to consult a specialist if there is any uncertainty,” said Prof. Dr. Herth.
Treatment with inhaled corticosteroids (ICS) plays a significant role in the management of patients with chronic obstructive pulmonary disease (COPD), particularly in the moderate and advanced stages of the disease.
The FLAME study, which plays a crucial role in the current discussion regarding therapy with inhaled corticosteroids, provided new insights into the treatment of COPD and compared the effects of the combination of LABA (long-acting beta-agonists) and LAMA (long-acting anticholinergics) with a standard combination of ICS and LABA in patients with moderate to severe COPD. The results showed that the combination of LABA and LAMA is superior in terms of reducing exacerbations and improving lung function. In addition, a lower risk of serious side effects associated with ICS therapy was observed, particularly respiratory tract infections. The FLAME study has far-reaching implications for COPD treatment. It demonstrates that the combination of LABA and LAMA is, in many cases, an equally effective—if not superior—alternative to ICS-containing therapy. This has led to a reassessment of the role of inhaled corticosteroids. In the current GOLD guidelines, which are based on the latest scientific evidence, ICS therapy is now more frequently restricted to patients with frequent exacerbations and severe disease progression, while the combination of LABA and LAMA is considered the preferred option for earlier stages of COPD.
“There is a need for discussion regarding inhaled therapy. In the past, both asthma patients and COPD patients were treated relatively similarly, and both groups were prescribed corticosteroid sprays. Thanks to the FLAME study, we now know that not every COPD patient benefits from a corticosteroid spray. With asthma, it’s exactly the opposite—corticosteroids are a must. That is why an accurate diagnosis is so crucial: Does the patient really have COPD, or is it more likely asthma? Otherwise, they may end up receiving a corticosteroid spray with all sorts of side effects, even though they don’t actually need it,” Prof. Dr. Herth notes critically.
COPD is considered an independent risk factor for the development of lung cancer—even independent of the common primary risk factor, smoking. Chronic obstructive pulmonary disease is characterized by persistent inflammation of the airways and lung tissue.
This persistent inflammatory activity leads to structural changes, DNA damage, and impaired cellular repair mechanisms, all of which can promote the development of cancer. Furthermore, processes such as oxidative stress, increased cell proliferation, and epigenetic changes promote carcinogenesis. Studies show that patients with COPD—especially those with severe lung function impairment—have a significantly increased risk of lung cancer, even if they have smoked for a comparable length of time as patients without COPD.
“COPD is considered an independent risk factor for lung cancer. This does not mean that every COPD patient will inevitably develop lung cancer, but the risk is significantly higher compared to someone who smokes but does not have COPD. How great one perceives the risk to be is, of course, always an individual assessment, but it is clear that the longer the damage persists, the higher the risk becomes,” Prof. Dr. Herth states at this point. Various preventive measures can be derived from this. The central approach remains consistent smoking cessation, as both COPD and lung cancer are largely triggered by smoking. In addition, early diagnosis plays a crucial role.
Non-pharmacological therapy plays a key role in the treatment of COPD and is particularly important for slowing the progression of the disease and improving patients’ quality of life.
A key component of this therapy is pulmonary rehabilitation, which—through regular physical activity and targeted training—strengthens the respiratory muscles, improves endurance, and increases patients’ physical capacity. “As far as pulmonary exercise groups are concerned, the training won’t allow the patient to repair their damaged lungs. But through targeted muscle training, their physical endurance improves noticeably. You can even measure this, for example, with the six-minute walk test. Healthy people can easily walk 600 meters, while COPD patients often manage only 300 meters at the start. With regular training, however, they can gain up to 100 meters. So the muscles are strengthened, and that helps them cope better with daily life despite their damaged lungs. It’s important that this training be continued throughout one’s life, just like other daily activities—10,000 steps a day would be a good goal,” Prof. Dr. Herth recommends encouragingly.
Especially in the advanced stages of COPD, pulmonary exercise helps maintain lung function and enables patients to enjoy greater independence in their daily lives. However, the acceptance and availability of pulmonary exercise programs are critical issues. Many regions have pulmonary exercise groups, but not all patients have access to them, particularly in rural areas or regions with limited healthcare infrastructure. The number of patients who actually benefit from such programs could also be higher if more attention were paid to the importance of this form of therapy.
The failure to routinely perform pulmonary function tests in primary care practices contributes significantly to the delayed diagnosis of COPD.
A key reason for the delayed diagnosis is the fact that pulmonary function testing—which is the gold standard for diagnosing COPD—is not routinely performed in many primary care practices. Although pulmonary function tests are often performed on patients with known risk factors, such as smokers, or when a respiratory disease is suspected, in many cases there is a lack of systematic and early diagnosis targeted at high-risk groups. This inadequate diagnostic approach delays the identification of the disease, which can negatively impact treatment options and prognosis.
“When it comes to prevention, specifically smoking cessation, there is a major problem: smoking cessation programs are not covered by health insurance in Germany. This means that patients must pay for them out of pocket—even though it would make sense from both a health and economic perspective to fund these programs. After all, most smokers do not come from the academic class but from other social groups that are often unwilling or unable to pay for such measures. Yet smoking cessation costs about 400 euros—roughly the same as what smoking costs many people in a month. From a pulmonological perspective, it would be highly desirable for these programs to be covered by health insurance, because in the long run they could prevent many cases of disease and save costs. The incidence of COPD is on the rise. This is due, in part, to the fact that as a society we are living longer and are therefore exposed to harmful environmental influences for longer periods of time. On the other hand, there is a clear gender effect: Women are affected more frequently today, but at the same time are still underdiagnosed. We have seen an increase particularly since the 1960s, when smoking patterns among women changed. Women also require a lower dose of smoke to develop the disease, which is likely due to hormonal factors. The average age at which lung cancer is diagnosed is also lower for women than for men,” notes Prof. Dr. Herth.
The lungs are one of the most important, yet often overlooked, organs in our body. This makes it all the more crucial to keep an eye on their health. Science and medicine are working intensively to develop new approaches for earlier diagnosis and more targeted treatment of lung diseases. Heidelberg University Hospital demonstrates how modern research and clinical care go hand in hand.
“The goal is to detect lung diseases earlier, diagnose them more accurately, and treat patients in a more personalized manner. Intensive research is being conducted toward this end.” Heidelberg University Hospital is part of the German Center for Lung Research (DZL), a research initiative in which various institutions collaborate on transnational research. The goal is to translate laboratory data more quickly into therapeutic options for patients. Heidelberg is among the most innovative hospitals in this field. This is also reflected in its regular placements in rankings such as those published by *Fokus* or *Stern*. So it’s not just about current patient care, but also about using research to treat future generations of patients earlier, more precisely, and more effectively,” notes Prof. Dr. Herth, and at the end of our conversation, he makes it clear:
“Smoking is deadly—and that’s especially true for the lungs. In addition, it’s recommended to ask your primary care physician for a lung function test when the opportunity arises. Many people don’t actively think about their lungs as long as they’re functioning properly. It’s only when symptoms arise that the issue comes to the forefront. Yet the lungs are often overlooked in preventive checkups. That’s why I advise having your lungs checked early on to detect potential problems in a timely manner.”
Thank you very much, Professor Dr. Herth, for this helpful information on COPD and the associated recommendations!
