{"id":13585,"date":"2025-11-15T06:00:00","date_gmt":"2025-11-15T11:00:00","guid":{"rendered":"https:\/\/cov19longhaulfoundation.org\/?p=13585"},"modified":"2025-10-20T21:24:20","modified_gmt":"2025-10-21T01:24:20","slug":"why-long-covid-causes-shortness-of-breath-and-what-were-learning-to-do-about-it","status":"publish","type":"post","link":"https:\/\/cov19longhaulfoundation.org\/?p=13585","title":{"rendered":"Why Long COVID Causes Shortness of Breath\u2014and What We\u2019re Learning to Do About It"},"content":{"rendered":"\n

Author<\/strong>: John Murphy Affiliation<\/strong>: COVID-19 Long-haul Foundation <\/p>\n\n\n\n

\ud83c\udf2c\ufe0f Introduction: When Breathing Doesn\u2019t Bounce Back<\/h2>\n\n\n\n

For many people recovering from COVID-19, the virus doesn\u2019t simply go away. Weeks or months later, they find themselves struggling to catch their breath\u2014sometimes after climbing stairs, sometimes just sitting still. This lingering symptom, known as dyspnea<\/strong>, is one of the most common and distressing features of Long COVID<\/strong>.<\/p>\n\n\n\n

In this article, we explore why shortness of breath persists in Long COVID, what\u2019s happening inside the body, how genetics and immune responses play a role, and what treatments are showing promise. We also highlight major studies and ongoing research efforts that are helping us understand\u2014and hopefully resolve\u2014this condition.<\/p>\n\n\n\n

<\/p>\n\n\n\n

\ud83d\udcca Epidemiology: How Common Is It?<\/h2>\n\n\n\n

Shortness of breath affects 26% to 56%<\/strong> of people with Long COVID, depending on the study and population. A 2024 Australian cohort study found that over half of long-haulers<\/strong> still experienced breathlessness six months after infection.<\/p>\n\n\n\n

Key Risk Factors:<\/h3>\n\n\n\n
    \n
  • Severe initial COVID-19 illness<\/li>\n\n\n\n
  • Hospitalization or ICU stay<\/li>\n\n\n\n
  • Female sex<\/li>\n\n\n\n
  • Pre-existing lung or heart conditions<\/li>\n<\/ul>\n\n\n\n

    \ud83d\udd2c What Causes It? The Multiple Layers of Dyspnea<\/h2>\n\n\n\n

    There\u2019s no single cause of post-COVID breathlessness. Instead, it\u2019s a multifactorial syndrome<\/strong> involving lungs, blood vessels, nerves, and the immune system.<\/p>\n\n\n\n

    1. Lung Damage and Fibrosis<\/strong><\/h3>\n\n\n\n

    COVID-19 can injure the tiny air sacs in the lungs (alveoli), leading to scarring<\/strong> or fibrosis<\/strong>. This makes the lungs stiff and less able to expand, reducing oxygen exchange. Studies from Stanford and the NIH show elevated levels of TGF-\u03b21<\/strong> and MMP9<\/strong>, which drive this scarring process.<\/p>\n\n\n\n

    2. Microvascular Injury<\/strong><\/h3>\n\n\n\n

    COVID-19 damages the lining of blood vessels, causing tiny clots and poor oxygen delivery. Elevated D-dimer<\/strong> and von Willebrand factor<\/strong> levels are common in long-haulers.<\/p>\n\n\n\n

    3. Autonomic Nervous System Dysfunction<\/strong><\/h3>\n\n\n\n

    Some patients develop POTS (Postural Orthostatic Tachycardia Syndrome)<\/strong> or vagus nerve dysfunction, which affects breathing rhythm and heart rate\u2014even when lungs are structurally normal.<\/p>\n\n\n\n

    4. Ongoing Inflammation<\/strong><\/h3>\n\n\n\n

    Even months after infection, many patients show elevated IL-6<\/strong>, TNF-\u03b1<\/strong>, and interferon<\/strong> levels. This chronic immune activation can affect lung tissue and breathing control.<\/p>\n\n\n\n

    \ud83e\uddec Genomic and Molecular Clues<\/h2>\n\n\n\n

    Genetic studies are helping us understand why some people develop persistent dyspnea while others recover quickly.<\/p>\n\n\n\n

    \ud83e\uddea GWAS Findings<\/h3>\n\n\n\n

    A 2025 genome-wide association study identified two key regions:<\/p>\n\n\n\n

      \n
    • Chromosome 3p21.31<\/strong>: Includes genes like CCR9<\/em> and SLC6A20<\/em>, linked to immune signaling and lung function.<\/li>\n\n\n\n
    • Chromosome 6p21.32<\/strong>: Contains HLA-DQA1<\/em>, associated with autoimmune responses.<\/li>\n<\/ul>\n\n\n\n

      \ud83e\uddec Transcriptomic Signatures<\/h3>\n\n\n\n

      Biopsies and blood samples show increased expression of:<\/p>\n\n\n\n

        \n
      • COL1A1<\/em> (collagen production)<\/li>\n\n\n\n
      • TGF-\u03b21<\/em> (fibrosis driver)<\/li>\n\n\n\n
      • MMP9<\/em> (tissue remodeling enzyme)<\/li>\n<\/ul>\n\n\n\n

        These genes suggest that fibrotic remodeling<\/strong> is a major contributor to breathlessness.<\/p>\n\n\n\n

        \ud83e\udde0 Mechanisms of Action: What\u2019s Actually Happening?<\/h2>\n\n\n\n

        \ud83e\udda0 Viral Persistence<\/h3>\n\n\n\n

        Fragments of SARS-CoV-2 RNA have been found in lung tissue months after infection, suggesting the virus may continue to provoke inflammation.<\/p>\n\n\n\n

        \ud83e\uddeb Fibrotic Remodeling<\/h3>\n\n\n\n

        Fibroblasts (scar-producing cells) become overactive, stiffening lung tissue and reducing elasticity.<\/p>\n\n\n\n

        \ud83e\udde0 Neuroimmune Crosstalk<\/h3>\n\n\n\n

        Inflammation in the brainstem and vagus nerve may alter how the body perceives breathlessness\u2014even when oxygen levels are normal.<\/p>\n\n\n\n

        \ud83e\ude7a Clinical Presentation and Diagnosis<\/h2>\n\n\n\n

        Common Symptoms:<\/h3>\n\n\n\n
          \n
        • Breathlessness during exertion or rest<\/li>\n\n\n\n
        • Chest tightness<\/li>\n\n\n\n
        • Fatigue and dizziness<\/li>\n\n\n\n
        • Rapid heartbeat or palpitations<\/li>\n<\/ul>\n\n\n\n

          Diagnostic Tools:<\/h3>\n\n\n\n
            \n
          • Pulmonary Function Tests (PFTs)<\/strong>: Measure lung capacity and airflow<\/li>\n\n\n\n
          • High-Resolution CT (HRCT)<\/strong>: Detects fibrosis and scarring<\/li>\n\n\n\n
          • Cardiopulmonary Exercise Testing (CPET)<\/strong>: Assesses oxygen use during activity<\/li>\n\n\n\n
          • Blood Tests<\/strong>: CRP, IL-6, D-dimer, ferritin<\/li>\n<\/ul>\n\n\n\n

            \ud83d\udc8a Treatment Options: What\u2019s Working?<\/h2>\n\n\n\n

            \ud83e\uddd8 Pulmonary Rehabilitation<\/h3>\n\n\n\n

            Structured breathing exercises and physical therapy improve lung function and stamina. Programs often include:<\/p>\n\n\n\n

              \n
            • Diaphragmatic breathing<\/li>\n\n\n\n
            • Pursed-lip breathing<\/li>\n\n\n\n
            • Gentle aerobic activity<\/li>\n<\/ul>\n\n\n\n

              \ud83d\udc89 Corticosteroids<\/h3>\n\n\n\n

              Used to reduce inflammation and slow fibrosis:<\/p>\n\n\n\n

                \n
              • Prednisone<\/strong>: Moderate potency, tapered over weeks<\/li>\n\n\n\n
              • Dexamethasone<\/strong>: High potency, used for acute flares<\/li>\n<\/ul>\n\n\n\n

                \ud83e\uddea Antifibrotic Drugs<\/h3>\n\n\n\n
                  \n
                • Nintedanib<\/strong> and pirfenidone<\/strong> are being tested for post-COVID lung fibrosis. Early results show promise in slowing scarring.<\/li>\n<\/ul>\n\n\n\n

                  \ud83e\uddec Biologics<\/h3>\n\n\n\n
                    \n
                  • Nintedanib<\/strong> (IL-6 blocker) and baricitinib<\/strong> (JAK inhibitor) may help modulate immune overactivation.<\/li>\n<\/ul>\n\n\n\n

                    \ud83d\udd0d Ongoing Research<\/h2>\n\n\n\n

                    \ud83e\udde0 NIH RECOVER Initiative<\/h3>\n\n\n\n

                    A $1.15 billion program studying Long COVID across organ systems. Includes pulmonary imaging, genomics, and symptom tracking.<\/p>\n\n\n\n

                    \ud83c\udf0d International GWAS Consortium<\/h3>\n\n\n\n

                    24 studies across 16 countries are mapping genetic risk factors for Long COVID symptoms, including dyspnea.<\/p>\n\n\n\n

                    \ud83e\uddea Stanford Pulmonary Fibrosis Trials<\/h3>\n\n\n\n

                    Investigating antifibrotic therapies and immune modulators in long-haulers with persistent breathlessness.<\/p>\n\n\n\n

                    \ud83e\udded Conclusion: A Complex Puzzle, Slowly Coming Together<\/h2>\n\n\n\n

                    Shortness of breath in Long COVID is not just a lingering symptom\u2014it\u2019s a sign of deeper biological disruption. From lung scarring and blood vessel damage to immune dysregulation and nervous system imbalance, dyspnea reflects a multi-system challenge.<\/p>\n\n\n\n

                    But thanks to genomic research, imaging advances, and targeted therapies, we\u2019re beginning to understand\u2014and treat\u2014this condition more effectively. Continued investment in research and patient-centered care will be key to helping millions breathe easier again.<\/p>\n","protected":false},"excerpt":{"rendered":"

                    Author: John Murphy Affiliation: COVID-19 Long-haul Foundation \ud83c\udf2c\ufe0f Introduction: When Breathing Doesn\u2019t Bounce Back For many people recovering from COVID-19, the virus doesn\u2019t simply go away. Weeks or months later, […]<\/p>\n","protected":false},"author":2,"featured_media":13593,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[56,90,108,242,1029,1339,1340,452,945,572,584,1322],"tags":[],"class_list":["post-13585","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blood-vessels","category-clots-bleeds","category-d-dimer","category-il-6","category-micro-clots","category-mmp9","category-nintedanib","category-postural-orthostatic-tachycardia-pots","category-shortness-of-breath","category-tgf-beta","category-thf-alpha","category-tnf-"],"_links":{"self":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/13585","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=13585"}],"version-history":[{"count":6,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/13585\/revisions"}],"predecessor-version":[{"id":13598,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/posts\/13585\/revisions\/13598"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=\/wp\/v2\/media\/13593"}],"wp:attachment":[{"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=13585"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=13585"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cov19longhaulfoundation.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=13585"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}