A simple blood test might soon tell doctors which older women face the worst
Among the millions quietly reshaped by long COVID, older women face a particular burden — one that may now be partially illuminated by something as ordinary as a blood test. Researchers in Chicago have found that elevated white blood cell counts predict the severity of long COVID symptoms in postmenopausal women, suggesting that inflammation, whether sparked by infection or already smoldering before it arrived, may be the hidden architect of prolonged suffering. The finding does not yet offer a cure, but it offers something medicine often undervalues: a way to see who is most at risk before the worst unfolds.
- Long COVID has quietly disabled millions, and postmenopausal women face a compounded crisis as the disease worsens cognitive decline already associated with aging.
- A third of the 1,200 women studied developed long COVID, with brain fog, memory loss, and confusion among the most common symptoms — and three-quarters suffered multiple symptoms at once.
- Researchers discovered that higher leukocyte counts independently predicted not just the presence of long COVID, but its intensity, even after accounting for other health variables.
- The mechanism is still contested — inflammation may be ignited by the infection itself, or it may have been present beforehand, quietly priming the body for a harder fall.
- A standardized, inexpensive blood test already available in every clinical lab could become a frontline tool for identifying high-risk patients before their symptoms spiral beyond control.
A simple blood test might soon help doctors identify which older women face the severest consequences of long COVID. Researchers at Rush University Medical Center in Chicago found that elevated white blood cell counts — specifically leukocytes, a marker of inflammation — correlate strongly with more severe long COVID symptoms in postmenopausal women. The findings, published in the journal Menopause, point toward a practical, low-cost screening tool for a condition that has quietly devastated millions.
The study drew on blood samples from more than 1,200 women enrolled in a COVID research program between mid-2021 and early 2022. Thirty-six percent developed long COVID, with cognitive symptoms dominating the picture: memory problems, brain fog, and difficulty concentrating were the most frequently reported complaints, and three-quarters of affected women experienced multiple symptoms simultaneously.
When researchers analyzed leukocyte counts across the group, a clear pattern emerged — women with higher white blood cell levels not only experienced more symptoms but experienced them more intensely. Lead author Ted Ng noted that the marker carries real clinical advantages: it is standardized, stable, widely available, and inexpensive. The mechanism behind the link remains uncertain, with researchers weighing whether COVID itself triggers damaging inflammation or whether pre-existing inflammation amplified the disease's impact.
The cognitive dimension carries particular weight. Dr. Monica Christmas of The Menopause Society emphasized that postmenopausal women already face elevated rates of cognitive impairment, and long COVID appears to deepen that burden significantly, often producing severe disability and a measurable decline in quality of life. For women already navigating the neurological shifts of aging, long COVID can feel like a compounding crisis.
The study does not resolve the problem, but it offers a foothold — a blood test that takes minutes and costs little could flag the highest-risk patients early, informing treatment decisions and guiding future research. Investigators themselves call for further study to confirm the leukocyte link and to determine whether inflammation precedes infection or follows it.
A simple blood test might soon tell doctors which older women face the worst of long COVID. Researchers at Rush University Medical Center in Chicago have found that elevated white blood cell counts—specifically leukocytes, a marker of inflammation in the body—correlate strongly with more severe long COVID symptoms in postmenopausal women. The discovery, published this week in the journal Menopause, offers what could become a practical, inexpensive screening tool for a condition that has quietly devastated millions.
The study examined blood samples from more than 1,200 women who participated in a COVID research program between June 2021 and February 2022. More than a third of them—36 percent—developed long COVID, the constellation of lingering symptoms that can persist for months or years after the initial infection clears. Among those affected, the most common complaints were cognitive: memory problems plagued 13 percent, brain fog clouded the thinking of 12 percent, and confusion or difficulty concentrating affected 11 percent. Three-quarters of the women with long COVID reported multiple symptoms simultaneously, compounding the burden.
When researchers compared leukocyte counts across the group, a pattern emerged. Women with higher white blood cell levels tended not only to experience more symptoms but to experience them more intensely. The connection held up even when researchers controlled for other variables, suggesting that leukocyte count functions as an independent predictor of severity. Ted Ng, an assistant professor at Rush's Institute for Healthy Aging and lead author of the study, noted that this marker has real advantages: it is standardized across laboratories, stable over time, widely available, and cheap to measure.
The mechanism remains uncertain. One leading theory holds that the initial COVID infection triggers a cascade of inflammation that damages tissues and organs, leaving lasting scars. But researchers acknowledge an alternative possibility: some of these women may have carried pre-existing inflammation before they caught COVID, and that underlying condition may have amplified the disease's impact. Both scenarios point to inflammation as the culprit, but the timing and origin of that inflammation remain open questions.
The cognitive dimension of long COVID deserves particular attention. Dr. Monica Christmas, associate medical director for The Menopause Society, emphasized that women already face elevated rates of cognitive impairment after menopause—memory loss, difficulty concentrating, the fog that can make ordinary tasks feel like wading through water. Long COVID appears to worsen this burden significantly, often leading to severe disability and a measurable decline in quality of life. For women already navigating the neurological changes of aging, the addition of long COVID symptoms can feel like a compounding crisis.
What makes this study valuable is not that it solves the problem, but that it offers a foothold. A blood test that costs little and takes minutes could identify which patients are at highest risk before symptoms spiral. That knowledge could inform treatment decisions, help patients understand what they face, and guide researchers toward interventions. But the work is preliminary. Researchers themselves call for further study to confirm the link between white blood cell counts and long COVID risk, and to untangle whether inflammation precedes infection or follows it. The next phase of investigation will determine whether this simple marker can actually change how doctors approach the disease.
Notable Quotes
Leukocyte count is a well-standardized, stable, widely available, and inexpensive clinical marker of inflammation that independently predicts long COVID severity in postmenopausal women— Ted Ng, assistant professor, Rush Institute for Healthy Aging
Long COVID significantly affects quality of life and causes severe disability, with particularly pronounced cognitive impairment in postmenopausal women— Dr. Monica Christmas, associate medical director, The Menopause Society
The Hearth Conversation Another angle on the story
Why does this matter for older women specifically? Couldn't this apply to anyone?
The study focused on postmenopausal women, and that's significant because menopause itself changes how the immune system works. Women already experience higher rates of cognitive problems after menopause—memory issues, brain fog. Long COVID seems to pile on top of that existing vulnerability, making the cognitive symptoms particularly severe.
So the inflammation is the common thread?
It appears to be. Whether the inflammation comes from the initial COVID infection or was already present before—that's still unclear. But in either case, women with higher white blood cell counts, which signal inflammation, ended up with worse symptoms.
A blood test sounds simple. Why hasn't this been caught before?
Long COVID itself is still relatively new as a recognized condition. Researchers are still mapping out what drives severity. This study is one piece of a larger puzzle. The leukocyte count is just a marker—it tells you inflammation is present, but not necessarily why or how to fix it.
What happens next? Does knowing your white blood cell count change treatment?
That's the honest answer: we don't know yet. Right now, this is a predictive tool. If confirmed in larger studies, it could help doctors identify high-risk patients earlier and potentially intervene before symptoms become severe. But the actual treatment—that's still being figured out.
How many women are we talking about here?
In this study, 36 percent of the 1,200 women developed long COVID. Three-quarters of those had multiple symptoms. So we're looking at hundreds of millions of women globally who could be affected. The cognitive symptoms—the brain fog, the memory problems—those are what people struggle with most.