COVID-19 hasn’t gone away, and neither has its long shadow.
Recent data from the California Department of Public Health show that the virus is surging again, with wastewater levels in the San Francisco Bay Area reaching highs not seen since last winter. Across the country, wastewater data and emergency department visits suggest a summer wave is gaining steam.
Yet, even as case numbers rise, much of the public — and some policymakers — continue to minimize the virus’s effect, dismissing it as “just a cold.” But COVID is often far more than a mild, short-lived illness. One of its most serious and poorly understood consequences is long COVID, a complex syndrome that can affect multiple organs and persist long after the initial infection.
First identified by patients, long COVID refers to a broad constellation of symptoms that linger for weeks or months after the virus clears. These can affect virtually every system in the body, but especially the cardiovascular and nervous systems.
In a landmark 2024 report, the National Academies of Sciences, Engineering, and Medicine defined long COVID as a “chronic condition” following SARS-CoV-2 infection, persisting for at least three months in a continuous, relapsing or progressive form. It can strike anyone — young or old, vaccinated or unvaccinated, healthy or chronically ill — and its manifestations are as varied as they are debilitating.
Heart disease has long been the leading cause of death in the United States, but COVID appears to be adding a new layer of risk — even for people without traditional risk factors.
A study from academic researchers, drawing on data from Britain, tracked more than 250,000 individuals who tested positive for COVID in 2020. Even three years later, those infected faced double the risk of heart attacks, strokes, and cardiovascular death compared to those who never tested positive, and this elevated risk did not diminish with time.
Worse still, individuals who had severe COVID requiring hospitalization were found to have a four- to seven-fold increase in their risk of serious cardiovascular events. That level of risk rivals that of people with coronary artery disease. In other words, surviving a severe case of COVID may put you in the same cardiovascular danger zone as someone with a long history of heart trouble.
The neurological effects of long COVID are no less troubling. Patients commonly report “brain fog,” memory lapses, difficulties concentrating, sensory hypersensitivities and extreme fatigue. Others develop more serious issues like dysautonomia — a disorder of the autonomic nervous system — or peripheral neuropathy.
Many of these symptoms overlap with those seen in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a mysterious and often marginalized illness that has long been associated with post-viral infection. Long COVID may finally bring to ME/CFS the attention — and research funding — it has long deserved.
Long COVID is unpredictable, but certain patterns are emerging. Women appear to be disproportionately affected, and people with pre-existing conditions or particular genetic markers may be more susceptible. Importantly, vaccination reduces — but does not eliminate — the risk of developing long COVID, primarily by preventing severe disease. However, some cases arise after mild or even asymptomatic infections.
Reinfections may also play a role, and the constantly mutating virus continues to pose challenges. Each new variant may interact differently with the body, potentially triggering long-term complications in unexpected ways.
Despite the millions affected, long COVID still lacks effective treatments. Clinical trials are underway, but the variability of symptoms and absence of clear diagnostic markers make it difficult to match patients with the right therapies. Tailored approaches that consider individual immune responses and organ-specific symptoms will likely be necessary.
In the meantime, patients often face a frustrating gauntlet of medical skepticism, inconsistent care, and social isolation. The National Academies’ report underscores the need for a compassionate, inclusive approach that takes patient experiences seriously, even in the absence of definitive lab tests.
Long COVID is a public health emergency and a scientific frontier. It exposes the limitations of our current medical model, which is often focused on acute illness rather than long-term, systemic dysfunction. It also compels the scientific community to examine closely post-viral conditions such as ME/CFS and the broader links among infection, inflammation and chronic disease.