Long COVID Research
Plain-Language Summaries of Current Scientific Evidence
Long COVID refers to a wide range of symptoms that persist or emerge after acute infection with SARS-CoV-2. Research into Long COVID is ongoing and spans multiple biological systems, with studies often producing complex and sometimes conflicting findings.
This page provides a centralized, plain-language overview of current peer-reviewed Long COVID research, organized by major symptom domains and biological mechanisms. Each linked article summarizes a specific study or review, focusing on what the evidence shows, what remains uncertain, and where limitations exist.
This page is updated regularly as new scientific research becomes available.
Autonomic Nervous System & Dysautonomia
Autonomic dysfunction, affecting heart rate, blood pressure, and digestion, is increasingly recognized as a common feature of Long COVID. Research in this area includes studies of orthostatic intolerance, postural orthostatic tachycardia syndrome (POTS), and related conditions.
- Study Estimates How Common Orthostatic Intolerance, POTS, and Low Blood Pressure Are in Long COVID
A systematic review and meta-analysis estimating how frequently autonomic problems occur in people with post-acute sequelae of COVID-19. - Similar Autonomic Nervous System Problems in Long COVID and ME/CFS
A comparative study showing overlapping autonomic dysfunction in Long COVID and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). - COVID-19–Induced Gastrointestinal Autonomic Dysfunction: A Systematic Review
A review examining how disruption of the autonomic nervous system may contribute to persistent gastrointestinal symptoms after COVID-19.
Immune System Dysregulation & Viral Persistence
Many studies suggest that ongoing immune activation, altered immune signaling, or persistence of viral components may play a role in Long COVID. Research in this category examines immune pathways, antibody responses, and potential biomarkers.
- A Specific Immune Pathway May Be Keeping the Immune System Overactive in Long COVID
A study identifying elevated activity in the lectin complement pathway, suggesting persistent immune activation. - Possible Long COVID Biomarker: Identification of SARS-CoV-2–Related Proteins in Serum Extracellular Vesicles
Research reporting detection of viral protein fragments in the blood of people with Long COVID more than a year after infection. - Patients With Post–COVID-19 Syndrome Show Enhanced Antibody Reactivity to Epstein–Barr Virus EBNA1
Findings indicating heightened immune responses to specific Epstein–Barr virus proteins in people with post-COVID symptoms. - Virus-Induced Endothelial Senescence as a Potential Driver of ME/CFS and Long COVID
A hypothesis paper proposing that viral infections may induce long-term dysfunction in blood vessel cells through immune-mediated mechanisms.
Neurological & Cognitive Findings
Neurological symptoms, including cognitive dysfunction, sensory changes, and neuropsychiatric effects, are commonly reported in Long COVID. Research in this area explores brain metabolism, inflammation, and biomarkers associated with neurological injury.
- Increased Phosphorylated Tau (pTau-181) Is Associated With Neurological Post-Acute Sequelae of COVID-19
A longitudinal study linking elevated plasma pTau-181 to neurological symptoms in people with Long COVID. - Reduced ATP-to-Phosphocreatine Ratios in Neuropsychiatric Post-COVID Condition
Magnetic resonance spectroscopy evidence suggesting altered brain energy metabolism in individuals with persistent neuropsychiatric symptoms. - Intestinal Barrier Compromise, Viral Persistence, and Immune Dysregulation Converge on Neurological Sequelae in Long COVID
A review proposing interconnected roles for gut barrier dysfunction, immune activation, and neurological inflammation.
Gastrointestinal Symptoms & Gut Involvement
Gastrointestinal symptoms are common in Long COVID and may persist independently or alongside systemic symptoms. Research in this area focuses on post-infectious IBS, gut–brain interactions, and intestinal barrier integrity.
- What We Know So Far About IBS After COVID-19
A review summarizing evidence that irritable bowel syndrome can develop following SARS-CoV-2 infection, with higher rates than in uninfected populations. - COVID-19–Induced Gastrointestinal Autonomic Dysfunction
Evidence that autonomic nervous system disruption may contribute to persistent digestive symptoms.
Long COVID in Children & Daily Functioning
While much Long COVID research focuses on adults, studies in children and adolescents show that prolonged symptoms can significantly affect daily functioning and quality of life.
- How Long COVID Impacts Children’s Ability to Function and Attend School
A large U.S. study reporting increased functional limitations and school absenteeism among children with persistent post-COVID symptoms.
What Long COVID Research Does Not Yet Show
Despite rapid progress, Long COVID research has important limitations. There is currently no single diagnostic test, no universally accepted biological marker, and no definitive explanation that applies to all patients. Findings often vary across studies due to differences in study design, populations, and symptom definitions.
Ongoing research aims to clarify mechanisms, identify reliable biomarkers, and better understand why symptoms differ so widely between individuals.
About These Summaries
All articles linked on this page summarize peer-reviewed scientific studies or reviews. Summaries are written in plain language and focus on evidence and limitations. They do not provide medical advice, diagnoses, or treatment recommendations.
For lived experiences related to Long COVID, ME/CFS, or POTS, readers are invited to share their stories separately.
Last updated: January 2026