Pulmonary FibrosisEdit

Pulmonary fibrosis is a chronic lung condition characterized by scarring (fibrosis) of the lung tissue. Over time, the scar tissue thickens and stiffens the lungs, making it harder for oxygen to pass into the blood. The most common form in adults is idiopathic pulmonary fibrosis (IPF), a progressive disease that often emerges in mid to late life. In IPF and related fibrotic lung diseases, the alveolar walls thicken and the normal lung architecture is disrupted, leading to reduced lung function and, in many cases, respiratory failure. Management focuses on slowing disease progression, maintaining quality of life, and supporting patients and families in practical ways. See Idiopathic pulmonary fibrosis and interstitial lung disease for broader context and related conditions.

The course of pulmonary fibrosis varies, but it is generally a chronic, progressive process. Symptoms typically begin gradually and include shortness of breath with activity and a persistent dry cough. As fibrosis advances, people may experience fatigue, chest discomfort, and reduced exercise tolerance. A physical exam may reveal crackling sounds in the lungs (inspiratory rales). Because the condition can mimic other lung disorders, diagnosis relies on a combination of history, imaging, physiology testing, and, when necessary, tissue assessment. See usual interstitial pneumonia for the pattern most commonly associated with IPF, and high-resolution computed tomography for the preferred imaging modality in many cases.

Definition and classification

Pulmonary fibrosis encompasses a spectrum of fibrotic lung diseases that share scarring of the lung interstitium. The term includes idiopathic forms, in which the cause is unknown, as well as fibrosis related to known factors such as environmental exposures, autoimmune diseases, or prior lung injuries. The most common idiopathic form is Idiopathic pulmonary fibrosis, which is typically associated with a UIP pattern on imaging and, when necessary, histology. Other fibrotic lung diseases are classified under interstitial lung disease and include connective tissue disease–associated ILD, hypersensitivity pneumonitis, occupational or environmental exposure–related fibrosis, and drug-induced fibrosis. See UIP pattern and pulmonary fibrosis—definition for more nuance.

Epidemiology and risk factors

IPF and related fibrotic diseases predominantly affect adults later in life, with the incidence rising with age. Men appear to be affected somewhat more often than women in IPF, and a history of cigarette smoking increases risk in several cohorts. Genetic predispositions have been identified, including variants in the MUC5B promoter and mutations in telomere-related genes such as TERT and TERC in some individuals, though most cases are sporadic. Environmental and occupational exposures, including certain dusts and fumes, may contribute to the development of non-idiopathic fibrotic lung disease; in these cases, the fibrosis is not IPF but a related ILD. See occupational exposure and genetic susceptibility for broader context.

Pathophysiology

Fibrosis results from an abnormal wound-healing response after lung injury. Repeated or sustained injury to the alveolar epithelium can trigger an exaggerated fibrotic repair process, leading to excess production of extracellular matrix and scarring that replaces normal lung parenchyma. The pattern of scar tissue in IPF is often described as UIP, with heterogeneous areas of normal lung alternating with fibrotic tissue and honeycombing. This architectural distortion impairs gas exchange and reduces lung compliance. See fibrosis and UIP for more detail.

Clinical presentation and diagnosis

People with pulmonary fibrosis typically notice increasing shortness of breath on exertion and a chronic cough over months to years. Other symptoms may include fatigue, weight loss, and reduced tolerance for activity. Diagnosis involves:

Medical history and physical examination
Pulmonary function testing, often showing a restrictive pattern with reduced diffusing capacity for carbon monoxide (DLCO)
Imaging, with HRCT revealing a UIP pattern in IPF in many cases
Histopathology from lung biopsy when imaging is inconclusive or when the diagnosis remains uncertain after multidisciplinary discussion
Exclusion of alternative causes of fibrosis, such as autoimmune disease or known exposures

A multidisciplinary approach, involving pulmonologists, radiologists, and pathologists, is commonly recommended to reach a confident diagnosis. See pulmonary function tests and HRCT as principal tools, and lung biopsy in selected cases.

Management and treatment

No cure exists for IPF, but several strategies can slow disease progression, improve symptoms, and enhance quality of life. Management often requires a combination of pharmacologic, supportive, and lifestyle approaches.

Antifibrotic medications: Two antifibrotic drugs have become standard therapy for IPF in many countries. pirfenidone and nintedanib slow the rate of decline in lung function in many patients and may slow disease progression. See antifibrotic therapy for a broader treatment context.
Supportive care: Vaccinations against respiratory pathogens, pulmonary rehabilitation, and careful management of comorbid conditions are important. See pulmonary rehabilitation and palliative care for applicable approaches.
Oxygen therapy: Supplemental oxygen may be required as fibrosis worsens and gas exchange becomes impaired. See oxygen therapy.
Lung transplantation: For selected patients with advanced disease, transplantation can extend survival and improve quality of life. See lung transplantation for criteria and process.
Lifestyle and risk reduction: Smoking cessation, avoidance of lung irritants, and regular follow-up to monitor progression are part of ongoing care.
Palliative care and end-of-life planning: As disease progresses, focusing on symptom relief, advance care planning, and family support becomes increasingly important. See palliative care.

In non-IPF forms of fibrotic ILD, treatment may target the underlying cause (for example, immunosuppression in autoimmune-related disease) in addition to strategies that control fibrosis. See interstitial lung disease for a broader framework.

Prognosis and outcomes

Prognosis in pulmonary fibrosis is variable. IPF often follows a chronic, progressive course with gradual decline in lung function, and median survival after diagnosis has historically been on the order of a few years, though recent advances in antifibrotic therapy have improved some outcomes for many patients. Individual prognosis depends on the degree of fibrosis at diagnosis, rate of progression, comorbid conditions, and response to therapy. Regular monitoring by a healthcare team is important to adjust treatment and supportive measures as needed. See prognosis and quality of life for related topics.

Controversies and debates

From a policy and practice perspective, several contentious issues shape how pulmonary fibrosis is managed and funded. In the discussion that follows, the emphasis is on practical considerations and policy trade-offs that often frame debates in health systems that prize patient autonomy and a robust role for private sector innovation.

Access and affordability of antifibrotic medications: Pirfenidone and nintedanib can be expensive, and insurance coverage varies. Proponents of market-based pricing argue that protecting drug research incentives is essential for future breakthroughs, while critics contend that high prices limit access for patients who need therapy. The balance between encouraging innovation and ensuring broad patient access is a core tension in health policy around IPF treatment.
The role of government price negotiation and regulation: Some systems consider centralized price setting or negotiation to reduce costs. Critics argue that aggressive price controls can dampen innovation and deter investment in future therapies, while supporters contend that patient access and affordability justify such measures.
Environmental and occupational risk management: There is ongoing debate about the extent to which public health regulation of air quality, occupational safety standards, and environmental exposures can reduce the incidence or progression of fibrotic lung disease. Policymakers weigh the costs of tighter regulations against the public health benefits of cleaner air and safer workplaces.
Screening and early detection: Guidelines vary on routine screening for at-risk populations. A conservative, right-leaning perspective may emphasize targeted, voluntary screening guided by clinical risk factors and patient choice, arguing against broad mandates that could raise costs without clear benefit.
Genetic testing and personalized medicine: Advances in genetics raise questions about when to test for predispositions (e.g., MUC5B or telomere gene variants) and how to use that information in care planning. Balancing patient privacy, cost, and potential benefits is an ongoing policy discussion.
End-of-life care and patient autonomy: As with other chronic, life-limiting diseases, discussions about transplantation eligibility, palliative care, and advance directives are central to patient-centered care. Some viewpoints emphasize patient autonomy and timely access to transplant and palliative options, while others stress careful resource stewardship and clinical judgment in complex cases.