Invisible Illness: Long COVID

Understanding Long COVID, Supporting Patients, Advancing Solutions

What Is Long COVID? Long COVID is a serious chronic disease that can affect multiple body systems and significantly disrupt daily life. Long COVID affects 5–7 % of U.S. adults—roughly 18 million people, according to the CDC. Long COVID remains an ongoing public health challenge requiring continued research, clinical innovation, and coordinated response.

Long COVID: A Multisystem Chronic Disease with National Impact

Long COVID is a distinct and multisystem condition with its own drivers, risk factors, and clinical course. It affects all ages, regions, and communities.

There is currently no single FDA-approved diagnostic test for Long COVID. Diagnosis is based on clinical evaluation, and individuals do not need a documented positive SARS-CoV-2 test to receive a diagnosis. Symptoms can vary widely and may fluctuate or relapse over time, making diagnosis and long-term management complex. Long COVID contributes to reduced workforce participation, disability, and significant economic burden, with national costs estimated in the hundreds of billions of dollars annually.

Long COVID requires focused, condition-specific research and care that reflect its distinct biology and clinical course. Although some symptoms overlap with other infection-associated chronic conditions and illnesses (IACCIs)—such as Lyme disease, Myalgic Encephalomyelitis / Chronic Fatigue Syndrome (ME/CFS), and other often “invisible” illnesses not readily apparent—similar presentations do not necessarily imply shared underlying mechanisms or treatments.

A new paradigm is needed to address complex chronic disease because fragmented, disease-by-disease, and organ-by-organ approaches are insufficient for understanding multisystem conditions like Long COVID. To overcome structural barriers—including siloed data, limited diagnostics, and inconsistent care pathways—HHS is advancing a disease-agnostic approach to strengthen data systems, clinical networks, and research infrastructure for invisible illnesses, accelerating measurable progress while preserving the distinctiveness and urgency of Long COVID.

Collage showing a hospital monitor with a patient in bed, hands holding in support, and a medical vial with yellow liquid.

Long COVID 101

What

A chronic disease following COVID-19 infection
It involves new, returning, or ongoing symptoms across multiple body systems
Symptoms vary and may include fatigue, cognitive impairment (“brain fog”), heart problems, respiratory symptoms, and other persistent health effects

Who

Tens of millions of Americans have reported Long COVID symptoms at some point in time
Can affect adults and children, including those with asymptomatic or mild initial illness

Where

Occurs nationwide, with higher prevalence in communities heavily impacted by COVID-19
Seen across urban, suburban, and rural settings

When

Symptoms may start during infection or emerge weeks later
Can persist for months or years, often in a relapsing-remitting pattern

Why It Matters

There is no single definitive diagnostic test for Long COVID
Persistent symptoms can impair daily functioning, work, school, and quality of life

By the numbers

~18 million

Approximate number of U.S. adults that reported having experienced Long COVID.

20%

Percentage of U.S. adults currently living with Long COVID that report their symptoms cause significant limitations to carry out daily activities.

Gold-Standard Science for Long Covid

CURE ID for Crowdsourcing Treatments that Work:
Cure ID helps find treatments and share novel uses of existing drugs, while exploring what others have tried. The goal is to identify potential treatments for diseases without good treatment options.

Clinical Guidelines:
The LymeX partnership is transforming 2025 Infection-Associated Chronic Illness (IACI) Guidelines into dynamic "Living" Evidence Guidelines for IACCIs (expected 2026) guidelines with clinical summaries, diagnostic considerations, and treatment insights from leading researchers and clinicians on Long COVID, Lyme disease, vaccine injury, IACCIs, and other illnesses that sometimes can be invisible.

Clinical Trials and Emerging Science:
Explore Long COVID trials ClinicalTrials.gov.

Next-Generation Diagnostics:
HHS is investing in AI-enabled diagnostics to improve the accuracy and early detection of Long COVID. Efforts include AI-enabled tools, epigenetic research, and molecular assays through a coordinated “OneHHS” approach across ARPA-H, CDC, CMS, FDA, NIH, other federal agencies, and external partners.

Radical Transparency for Long COVID

TOPx HHS Sprint for Invisible Illness
Fueled by HHS Open Data, this 12-week sprint with industry, academia, and the public will build digital tools and insights for Long COVID, invisible illness, and the cost of illness with cash prizes for winning submissions.

HHS Open Data
Unleash the power of HHS Open Data for the public and policymakers to drive innovation and economic activity, accelerate scientific research, and strengthen the foundation of an open and transparent government.

HHS Open Source
Code for public use and reuse, including “LymeX AI” repos for the diagnostic companies, American innovators, and entrepreneurs to optimize FDA submission packages and move new diagnostic tests from lab to market.

Open Science - Science.gov
Access millions of authoritative scientific research results from HHS, NIH, and federal science agencies.

Believe and Empower Patients as Partners

HHS Long COVID Roundtable
National forum convened by Secretary Kennedy with Members of Congress to accelerate solutions with patients and partners for Long COVID.

Living Evidence Guidelines
HHS and LymeX partners are transforming 2025 Infection-Associated Chronic Illness (IACI) guidelines into dynamic "Living" Evidence Guidelines for IACCIs--expected 2026--that will update every six months, as more science becomes known.

Clinician Locator [Coming soon in 2026]
Clinician locator with national provider directory and information on doctors who are treating Long COVID, Lyme disease, IACCIs, and invisible illnesses.

Patient Resources [Coming soon in 2026]

Co-Create Solutions with HHS

Whether you are living with Long COVID, caring for someone affected, contributing scientific expertise, or driving innovation, your participation helps advance solutions.

Share your insights. Participate in research. Engage with federal initiatives. Help improve understanding of Long COVID.

Image for CURE ID for Crowdsourcing Treatments that Work

Help find treatments and share novel uses of existing drugs, while exploring what others have tried. The goal is to identify potential treatments for diseases without good treatment options.

Image for Invisible Illness Patient-Centered Innovation

Co-create the future of invisible illnesses, including a 12-week sprint fueled by HHS Open Data with industry, academia, and the public will build digital tools with, by, and for the people.

HHS and LymeX partners are transforming 2025 Infection-Associated Chronic Illness (IACI) guidelines into dynamic “Living” Evidence Guidelines for IACCIs—expected 2026—that will update every six months, as more science becomes known.