Study findings updated . AI-assisted evidence summary, not individual medical advice or a clinician endorsement.
THE SHORT VERSION
What’s worth knowing.
The key findings, what they mean, and the context that matters.
THE HEADLINE TAKEAWAY95% judged COVID deathsdefinite, probable or possible COVID-19 deaths among people autopsied; 5% were not
Autopsies judged almost all deaths with the virus to be COVID deaths.
Pathologists autopsied everyone in one region who died with the virus. They classed 95% as COVID-19 deaths (definite, probable or possible); only 5% were not. In six people, the infection was found only by a swab taken after death. Deep vein thrombosis, meaning blood clots in deep veins, turned up in 40%.
It answers the claim that people died 'with' COVID rather than 'from' it: when pathologists looked directly, the virus was judged a cause in almost every case, and some infections surfaced only after death. Early-pandemic autopsies in Hamburg, Germany, of people aged 52 to 96, nearly all with serious prior illnesses; 'possible' cases had an equally likely other cause.
See the evidence
Full autopsies of the first 80 consecutive people who died with a PCR-confirmed infection in Hamburg, Germany, where autopsy was ordered for all such deaths early in the pandemic.
From the study: “A total of 76 cases (95%) were classified as COVID-19 deaths, corresponding to categories 1-3.”
95% judged COVID deaths
Edler C et al. Dying with SARS-CoV-2 infection-an autopsy study of the first consecutive 80 cases in Hamburg, Germany. International journal of legal medicine. 2020.
From the study: “In six cases, SARS-CoV-2 infection was diagnosed postmortem by a positive PCR test in a nasopharyngeal or lung tissue swab.”
95% judged COVID deaths
Edler C et al. Dying with SARS-CoV-2 infection-an autopsy study of the first consecutive 80 cases in Hamburg, Germany. International journal of legal medicine. 2020.
From the study: “Overall, deep vein thrombosis has been found in 40% of the cases.”
95% judged COVID deaths
Edler C et al. Dying with SARS-CoV-2 infection-an autopsy study of the first consecutive 80 cases in Hamburg, Germany. International journal of legal medicine. 2020.
COVID lungs had tiny clots 9 times as often as flu lungs.
9× as common as in fluhow often tiny clots appeared in lung air-sac capillaries, COVID-19 vs flu deaths
Pathologists compared lungs from people who died of COVID-19 with lungs from people who died of influenza-related lung failure. COVID-19 lungs showed widespread clotting in their blood vessels: tiny clots in air-sac capillaries (microthrombi) were 9 times as common as with influenza, and growth of new blood vessels was 2.7 times as high.
COVID-19 is not simply a bad flu: it attacks the lungs' blood vessels as well as their air sacs, helping explain why blood clots became a major concern in severe illness. A tiny early-pandemic autopsy series of 7 COVID-19 and 7 influenza lungs; the authors say how universal these changes are needs more research.
See the evidence
Autopsy lungs from 7 people who died of COVID-19, 7 who died of lung failure from H1N1 influenza and 10 uninfected people, studied with microscopy, 3D imaging and gene tests.
From the study: “Alveolar capillary microthrombi were 9 times as prevalent in patients with Covid-19 as in patients with influenza (P<0.001).”
9× as common as in flu
Ackermann M et al. Pulmonary Vascular Endothelialitis, Thrombosis, and Angiogenesis in Covid-19. The New England journal of medicine. 2020.
From the study: “the amount of new vessel growth - predominantly through a mechanism of intussusceptive angiogenesis - was 2.7 times as high as that in the lungs from patients with influenza (P<0.001).”
9× as common as in flu
Ackermann M et al. Pulmonary Vascular Endothelialitis, Thrombosis, and Angiogenesis in Covid-19. The New England journal of medicine. 2020.
Leftover virus in tissue after mild COVID was linked to long COVID.
5.2× odds of long COVIDhigher odds of long COVID symptoms when virus RNA lingered after mild COVID-19
In people who had recovered from mild COVID-19 and had tissue removed for other medical reasons, virus RNA turned up in 30% of samples at 1 month and 11% at 4 months, across ten tissue types including brain, liver and lung. People with leftover virus RNA had 5.2 times the odds of long COVID symptoms compared with those without it.
Even a mild infection may leave viral traces in organs for months, a physical clue to why some people stay unwell long after the illness itself has passed. A single-hospital study in Beijing after the omicron wave, in people already needing surgery or scopes; it shows a link, not that leftover virus causes long COVID.
See the evidence
Leftover surgical, endoscopy and blood samples from 225 people at one Beijing hospital, collected 1 to 4 months after mild omicron infection in 2023, with a phone check at 4 months.
From the study: “Detection of viral RNA in recovered patients was significantly associated with the development of long COVID symptoms (odds ratio 5·17, 95% CI 2·64-10·13, p<0·0001).”
5.2× odds of long COVID
Zuo W et al. The persistence of SARS-CoV-2 in tissues and its association with long COVID symptoms: a cross-sectional cohort study in China. The Lancet. Infectious diseases. 2024.
From the study: “Viral RNA was detected in 16 (30%) of 53 solid tissue samples collected at 1 month, 38 (27%) of 141 collected at 2 months, and seven (11%) of 66 collected at 4 months.”
5.2× odds of long COVID
Zuo W et al. The persistence of SARS-CoV-2 in tissues and its association with long COVID symptoms: a cross-sectional cohort study in China. The Lancet. Infectious diseases. 2024.
From the study: “Viral RNA was distributed across ten different types of solid tissues, including liver, kidney, stomach, intestine, brain, blood vessel, lung, breast, skin, and thyroid.”
5.2× odds of long COVID
Zuo W et al. The persistence of SARS-CoV-2 in tissues and its association with long COVID symptoms: a cross-sectional cohort study in China. The Lancet. Infectious diseases. 2024.
In some patients, virus RNA lingered in body and brain for months.
Up to 230 daysafter symptoms began, virus RNA was still in body and brain in one patient
Full autopsies of 44 people who died with COVID-19 found the virus's genetic material (RNA) spread widely through the body. In one person it was still present in many sites, including throughout the brain, 230 days after symptoms began. Yet outside the airways and lungs, there was little sign of inflammation or of the virus directly killing cells.
The virus can linger in organs, including the brain, for months, a possible clue to long COVID. But finding viral traces was not the same as finding damage, which is partly reassuring. Autopsies of people who died, mostly of severe COVID-19; the 230-day finding comes from a single patient, so how often virus lingers this long is unknown.
See the evidence
Complete autopsies of 44 people who died with COVID-19, 11 with detailed brain sampling, spanning deaths from early infection to more than seven months after symptoms began.
From the study: “Further, we detected persistent SARS-CoV-2 RNA in multiple anatomic sites, including throughout the brain, as late as 230 days following symptom onset in one case.”
Up to 230 days
Stein SR et al. SARS-CoV-2 infection and persistence in the human body and brain at autopsy. Nature. 2022.
From the study: “Despite extensive distribution of SARS-CoV-2 RNA throughout the body, we observed little evidence of inflammation or direct viral cytopathology outside the respiratory tract.”
Up to 230 days
Stein SR et al. SARS-CoV-2 infection and persistence in the human body and brain at autopsy. Nature. 2022.
After COVID, placenta destruction, not fetal infection, likely caused these stillbirths.
77.7% of the placentaaverage share of placenta destroyed in stillbirths and newborn deaths after COVID-19
Pathologists examined virus-positive placentas from stillbirths and newborn deaths after the mother had COVID-19. On average, destructive inflammation of the placenta (placentitis) involved 77.7% of its tissue. Deaths likely came from the failing placenta starving the baby of oxygen; there was no evidence that infection of the baby itself caused them.
A mother's infection can endanger her baby by wrecking the organ that delivers its oxygen, even when the virus is not harming the baby's own organs. A selected series of only fatal cases, so it cannot say how often COVID-19 in pregnancy leads to stillbirth.
See the evidence
A review by 44 specialists in 12 countries of placentas and autopsies from 64 stillborn babies and 4 newborn deaths whose placentas tested positive for the virus.
From the study: “Severe destructive placental disease from SARS-CoV-2 placentitis averaged 77.7% tissue involvement.”
77.7% of the placenta
Schwartz DA et al. Placental Tissue Destruction and Insufficiency From COVID-19 Causes Stillbirth and Neonatal Death From Hypoxic-Ischemic Injury. Archives of pathology & laboratory medicine. 2022.
From the study: “In these cases, intrauterine and perinatal death likely results directly from placental insufficiency and fetal hypoxic-ischemic injury.”
77.7% of the placenta
Schwartz DA et al. Placental Tissue Destruction and Insufficiency From COVID-19 Causes Stillbirth and Neonatal Death From Hypoxic-Ischemic Injury. Archives of pathology & laboratory medicine. 2022.
From the study: “There was no evidence that SARS-CoV-2 involvement of the fetus had a role in causing these deaths.”
77.7% of the placenta
Schwartz DA et al. Placental Tissue Destruction and Insufficiency From COVID-19 Causes Stillbirth and Neonatal Death From Hypoxic-Ischemic Injury. Archives of pathology & laboratory medicine. 2022.
Heart-muscle inflammation turned out to be rare in COVID autopsies.
Myocarditis under 2%likely true rate of heart-muscle inflammation across 277 autopsied hearts
Pooling 277 hearts examined after death from COVID-19, a review found that myocarditis (inflammation of the heart muscle), much discussed early in the pandemic, was likely present in under 2%. But the heart was not untouched: at least one other COVID-related heart finding was reported in 47.8%.
Early alarm that the virus commonly inflames the heart muscle was overstated, but the heart was still often harmed in other ways in people who died. Pooled published 2020 autopsy reports of mostly older people with other illnesses, which recorded findings inconsistently, so exact rates are uncertain.
See the evidence
A literature review pooling 277 hearts autopsied after COVID-19 from published case series in 10 countries, searched in 2020.
From the study: “the true prevalence of myocarditis is likely much lower (<2%).”
Myocarditis under 2%
Halushka MK et al. Myocarditis is rare in COVID-19 autopsies: cardiovascular findings across 277 postmortem examinations. Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology. 2021.
From the study: “In conclusion, across 277 cases, COVID-19-related cardiac histopathological findings, are common, while myocarditis is rare.”
Myocarditis under 2%
Halushka MK et al. Myocarditis is rare in COVID-19 autopsies: cardiovascular findings across 277 postmortem examinations. Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology. 2021.
From the study: “At least one COVID-19-related cardiovascular histopathologic finding (all of the above except amyloidosis) was reported in 47.8% of cases where this could be determined.”
Myocarditis under 2%
Halushka MK et al. Myocarditis is rare in COVID-19 autopsies: cardiovascular findings across 277 postmortem examinations. Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology. 2021.
All autopsied brains were injured, yet virus in them was scant.
All 41 brains injuredshowed low-oxygen (hypoxic/ischemic) damage among people who died with COVID-19
In 41 people who died with COVID-19, every brain showed significant damage, most often from lack of oxygen and blood flow (hypoxic/ischemic injury). Virus levels in the brain were very low and did not match the damage. The authors say the brain immune-cell activation they saw more likely came from body-wide inflammation, perhaps with low oxygen, than from direct brain infection.
Severe COVID-19 can harm the brain without the virus invading it, so the threat comes from what the illness does to the whole body, including its oxygen supply. Autopsies at one New York hospital of mostly older, very ill patients, 83% Hispanic/Latinx, with no uninfected brains for comparison.
See the evidence
Consecutive autopsies of 41 people who died with COVID-19 at Columbia University Irving Medical Center in New York, with 20 to 30 brain areas examined in each.
From the study: “In our single centre study of 41 consecutive autopsies of COVID-19 patients we found significant neuropathology in all brains, most commonly diffuse hypoxic/ischaemic damage”
All 41 brains injured
Thakur KT et al. COVID-19 neuropathology at Columbia University Irving Medical Center/New York Presbyterian Hospital. Brain : a journal of neurology. 2021.
From the study: “Our findings indicate that the levels of detectable virus in coronavirus disease 2019 brains are very low and do not correlate with the histopathological alterations.”
All 41 brains injured
Thakur KT et al. COVID-19 neuropathology at Columbia University Irving Medical Center/New York Presbyterian Hospital. Brain : a journal of neurology. 2021.
From the study: “do not result from direct viral infection of brain parenchyma, but more likely from systemic inflammation, perhaps with synergistic contribution from hypoxia/ischaemia.”
All 41 brains injured
Thakur KT et al. COVID-19 neuropathology at Columbia University Irving Medical Center/New York Presbyterian Hospital. Brain : a journal of neurology. 2021.
Placenta-destroying COVID stillbirths were reported only in unvaccinated mothers.
All mothers unvaccinatedin every reported stillbirth or newborn death caused by placenta infection
This expert review of published cases found that whenever virus infection of the placenta (placentitis) was reported to cause a stillbirth or newborn death, the mother had not been vaccinated against COVID-19. The authors think placentitis likely follows virus getting into the mother's bloodstream at some point in pregnancy.
It hints that vaccination may help protect the placenta in pregnancy, though this is a pattern seen in case reports, not a measured effect. A review of published case reports rather than a comparison study, and the authors say the pattern does not constitute proof that vaccination prevents placentitis.
See the evidence
An expert review in an obstetrics journal pulling together published reports on COVID-19 placenta infection, stillbirth and maternal vaccination.
From the study: “An important observation is that in all reported cases of SARS-CoV-2 placentitis causing stillbirth and neonatal death, the mothers were unvaccinated.”
All mothers unvaccinated
Schwartz DA et al. SARS-CoV-2 placentitis, stillbirth, and maternal COVID-19 vaccination: clinical-pathologic correlations. American journal of obstetrics and gynecology. 2023.
From the study: “SARS-CoV-2 placentitis is likely the result of an episode of SARS-CoV-2 viremia at some time during the pregnancy.”
All mothers unvaccinated
Schwartz DA et al. SARS-CoV-2 placentitis, stillbirth, and maternal COVID-19 vaccination: clinical-pathologic correlations. American journal of obstetrics and gynecology. 2023.
Autonomic nerve density was lower despite preserved epidermal fiber density
In the 23-patient painful Long COVID subgroup with normal intraepidermal nerve-fiber density, autonomic fiber density around piloerector muscles and sweat glands was lower than in healthy controls.
This was a selected retrospective biopsy subgroup. The group comparison does not establish diagnostic accuracy, a causal mechanism or a treatment response.
Study details & original results
Falco, Pietro et al.. Autonomic small fiber involvement in painful long COVID: a histological and clinical study.. Frontiers in Human Neuroscience. 2026.
Autonomic piloerector-muscle and sweat-gland nerve-fiber density compared with healthy controls in the 23-patient painful Long COVID subgroup with normal intraepidermal nerve-fiber density; selected retrospective biopsy study.
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WHEN YOU WANT TO GO DEEPERSee all 1 findingsOriginal results, comparisons and study details.
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SOURCE 011 finding
Falco, Pietro et al.. Autonomic small fiber involvement in painful long COVID: a histological and clinical study.. Frontiers in Human Neuroscience. 2026.
Autonomic piloerector-muscle and sweat-gland nerve-fiber density compared with healthy controls in the 23-patient painful Long COVID subgroup with normal intraepidermal nerve-fiber density; selected retrospective biopsy study.
Browse the 9 original sourcesThe complete bibliography behind this monitor.
[1]
Falco, Pietro et al.. Autonomic small fiber involvement in painful long COVID: a histological and clinical study.. Frontiers in Human Neuroscience. 2026.
Edler C et al. Dying with SARS-CoV-2 infection-an autopsy study of the first consecutive 80 cases in Hamburg, Germany. International journal of legal medicine. 2020.
Zuo W et al. The persistence of SARS-CoV-2 in tissues and its association with long COVID symptoms: a cross-sectional cohort study in China. The Lancet. Infectious diseases. 2024.
Schwartz DA et al. Placental Tissue Destruction and Insufficiency From COVID-19 Causes Stillbirth and Neonatal Death From Hypoxic-Ischemic Injury. Archives of pathology & laboratory medicine. 2022.
Halushka MK et al. Myocarditis is rare in COVID-19 autopsies: cardiovascular findings across 277 postmortem examinations. Cardiovascular pathology : the official journal of the Society for Cardiovascular Pathology. 2021.
Thakur KT et al. COVID-19 neuropathology at Columbia University Irving Medical Center/New York Presbyterian Hospital. Brain : a journal of neurology. 2021.
Schwartz DA et al. SARS-CoV-2 placentitis, stillbirth, and maternal COVID-19 vaccination: clinical-pathologic correlations. American journal of obstetrics and gynecology. 2023.
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