Understanding Long COVID: What Every Patient Needs to Know

Hello, I'm Dr. Michael Brode. I am an internal medicine physician and medical director of our post-COVID 19 program at UT Health Austin, which is part of the University of Texas Dell Medical School. And today, I really want to try to demystify

long

COVID,

what

it looks like when seeing

patient

s, and

what

emerging science and research tells us about this disease. So the first thing I always start as a history buff is to say that post-viral diseases are not new. We have seen fatigue and neurological symptoms after previous pandemics like the Spanish flu or even the original SA virus.

So when we talk about

long

COVID, it's a question of what is a virus that we have never seen on this scale in modern times versus what is the cause of the particular COVID 19 virus. And long COVID is probably a confluence of both phenomena. I think the first part that gets a little confusing is what is this disease called? And I think most people have settled on calling it long COVID, although the medical term is post-acute sequelae of COVID 19 or PASC. Some people call it a post-COVID condition and

patient

s themselves may refer to themselves as long-haulers.

At this time, there is no consensus definition or even diagnostic test that can diagnose long COVID. But most experts agree that if symptoms started after long COVID and there is no alternative medical explanation for the symptoms and they last more than four weeks, it is probably long COVID. However, what we do

know

is that the initial active COVID infection can last up to four weeks. People have rapid healing during that time. It slows down for four to 12 weeks and then healing stabilizes. Typically, around 12 weeks, the symptoms that still exist are the ones most likely to persist.

And that's when most experts will say long COVID begins 12 weeks after the initial infection. I also think the framework for

understanding

long COVID can be overwhelming. Some research has said that there are more than 50 symptoms. Other investigations, more than 100 and the only article that takes the cake, identified 203 symptoms of long COVID. I really organize it into three main categories. The first is, what damage to the body or tissues can we detect in our traditional tests? And that can be lung scarring, and that occurs almost exclusively in patients who were hospitalized or had serious illnesses that required being in the hospital and receiving oxygen.

The next category is new chronic diseases after COVID 19 infection. And there is research that suggests that people are more likely to develop diabetes, blood clots, fatty liver disease or stroke after a COVID 19 illness than not. So for those two things, you

know

, having detectable organ damage from a serious illness or having a new condition, most people don't think of them as long COVID because those are detectable problems that we have treatments based on. evidence. And most people would consider it a post-COVID condition. LONG COVID, on the other hand, is more of this syndrome of symptoms in the absence of an identifiable problem in a laboratory test.

And this is kind of a mystery illness or strange symptoms that people are developing, which we rather think of as long COVID. So, within that syndrome, in these new and mysterious symptoms. I really grouped those symptoms into three categories. The first is post-viral symptoms. And then, you know, cough, shortness of breath, muscle pain, joint pain or almost headaches, if people got this flu-like viral illness and it never went away and those symptoms never got better. The next category is neurological or inflammation symptoms. This actually manifests itself most prominently in neurological problems of the autonomic nervous system.

That's the automatic part of the nervous system, the part that controls heart rate, blood pressure, bowel movement, and temperature regulation. And we're really seeing that with long COVID, there can be a lot of new neurological symptoms after COVID infection. The last category, which is almost universal among people with long COVID, is fatigue, brain fog, and a medical term called post-exertional malaise, which simply describes the phenomenon of if you do an activity that normally wouldn't make you tired and you just feel tired. wears out. and makes all your problems worse. And I have observed that those three things are interrelated.

You know, fatigue is real and that's the most common symptom of long COVID. And the brain fog when we do formal testing is actually deficits in concentration, attention, and processing, and on formal testing, most people can compensate and do quite well. But in the real world, it really rears its head. So the word is on the tip of my tongue. I walk into the living room and I don't remember why or I just have a lot of trouble concentrating and what it seems like is that it seems to be very clearly related to fatigue. And that makes sense.

The brain is the most metabolically active organ in the body, so it uses and can deplete the battery as much as physical exercise. And the terrible thing about long COVID is that if you drain the battery too much, you hit a wall and pay for it. You experience post-exertional discomfort and all your symptoms worsen. So for a long time, there is no discrete definition of COVID. People can range from having organ damage to having new diseases like diabetes and having these mysterious symptoms. It's not always perfect, but I think those categories of symptoms are what most people think about when they think about long COVID.

The next question is, well, how many people have long COVID? And the answer is a lot. The CDC estimates that 15% of the total US population has had long COVID at some point. There are almost 40 million Americans. They also estimate that 6% of people still have long COVID. There are 15 million Americans. And right now they estimate that 5 million people are out of the workforce because long COVID can be disabling and there will be half a trillion dollars in additional medical costs for our society. Many people are going through this and this will have many repercussions of the pandemic that will stay with us.

The next question is who gets long COVID? And while we don't know for sure who is most at risk, there are two main categories. The first is pretty obvious: The people who get sicker and are at higher risk of getting sick from COVID are the ones most likely to develop long COVID. And that includes people who may be overweight, diabetic, or elderly. They are the ones most at risk of being hospitalized and having those persistent symptoms. The next category is a little less obvious and I consider that of people's underlying immune system. And so people who have autoimmune diseases or have some low level of autoimmunity, even if they don't have a diagnosed autoimmune disease, seem predisposed to having long COVID.

People with connective tissue disorders, asthma. Also within that, women seem to have more long COVID than men. And once again, women appear to be more predisposed than men to developing autoimmune disorders. So it seems like there may be a connection there. Lastly, and I think this is an important area of ​​research, is that people who have virus reactivation in their bodies may be more predisposed to developing long COVID. And the great example is the Epstein-Barr virus, EBV. It is the virus that causes mononucleosis. Some research shows that during active COVID infection, if it is reactivated and released in the body, they are more likely to develop long COVID symptoms.

Although it is important to note that when people are measured months later, the virus is usually no longer in their blood. Therefore, it is not clear whether these viruses like EBV are directly causing the symptoms or are simply part of the problems with the immune system response and inflammation from having the infection. That always leads to the next question: what is happening? What is causing long COVID and what is the mechanism? And right now we don't know for sure. There is no diagnostic test or specific set of symptoms that diagnose long COVID. And when we can send a blood test to the laboratory to diagnose it and learn the mechanism that will lead to a medical advance, that will win someone a Nobel Prize.

But right now we don't have it. Right now, however, the leading theory of long COVID is that it is caused by immune system dysfunction. The immune system protects the body from threats, bacteria and viruses. But when it becomes too active, it can start to cause problems like inflammation or attack the body itself. Within that, there are some theories that there are viral fragments in the body that could be causing that chronic inflammation, which induces autoimmunity. Then the body attacks itself. Or maybe there are even problems with the vasculature, microcoagulation and problems, blood flow throughout the body or signals within the nervous system.

And there is some new and emerging research that can actually say that all of those things are happening. We don't fully understand the mechanism. Some suggest that these viral fragments are causing chronic inflammation, which decreases serotonin and causes neurological signaling problems and even these microclots, although this is preliminary research that will have to be validated in larger populations despite not having discovered the mechanism. exact. . There are two things in the research that really stand out to me and come up again and again. The first is that neurological inflammation is clearly occurring. What we're seeing is that in some research, the part of the brain that's supposed to keep inflammation away actually activates and that decreases blood flow to the part of the brain that controls concentration, attention processing, and even memory parts of the brain. brain.

And many patients described being in this kind of fight or flight response. They are more irritable than before. They have less reservations or anxiety than ever before the infection. So while most people experience inflammation in the brain, a subset of patients may also experience it peripherally in the small nerves in their body. And so, once again, it's the autonomic nervous systems that control heart rate, blood pressure, and temperature regulation. And some studies show that nearby nerves may be damaged or not function properly with long COVID. The next category of research really looks at exercise testing, where they take young, healthy people who now have long COVID and put them on a treadmill and see how they do.

And unfortunately, people with long COVID don't do well exercising on a treadmill, but it's for a very specific reason. When they start moving, their heart pumps, the blood, their lungs put oxygen into the blood. But for some reason, the blood returns to the heart full of oxygen that the body never used. And then it is a fundamental question: why? Some research suggests it is a cellular metabolism problem. The body has to convert oxygen into energy. Other research suggests it may be a blood flow problem. You know, the body has to get blood flowing to the right place at the right time and extract that oxygen efficiently so it can be used for energy.

Like

every

thing, a combination of both is probably happening. But what we see with people on the treadmill is that when they start exercising, they start to create an energy deficit because they're not using that oxygen. And that tells the brain to fix it. And how does the brain solve it? Well, your heart rate increases. They start breathing faster. They start to feel terrible in their chest and short of breath. But there is nothing wrong with the heart or lungs. It is simply the body trying to supply more oxygen and compensate for what is fundamentally an energy problem.

And in these same tests, people don't do well on the treadmill the first day. But if we bring them back the next day and try again, they do terribly. They have post-exertional discomfort and have less exercise capacity after developing that deficit. Finally, how do we approach long COVID patients? And my first step is always to believe the patient. It is absolutely a real disease that affects millions of Americans. And it's important to recognize that because it seems to be affecting women and women of color more than other people. And that's a group that doctors in the medical community have historically diminished or disbelieved in.That is why we must be humble, even if we cannot explain it.

This is a real disease that affects millions of people. And just listen to the patients. The next thing is that we really need to make sure that it is not other medical problems that are causing this condition. Heart disease, diabetes, and thyroid problems are common in the general population and can overlap with many of these symptoms. Therefore, it is important to make sure that those things are not causing the problems or, if you have those problems, that they are well managed and not contributing. The next step is to detect mental health symptoms. I would say anxiety is part of the neuroinflammatory response to long COVID and depression is just part of being alive for the past three years.

But, you know, whether it's physiological from the virus or just, you know, dealing with a chronic, disabling illness without dealing with mental health symptoms, we're not going to have a foundation for recovery. And I also get into people's social lives and their financial

needs

. Again, this can be a disabling illness. And if people are worried about losing their housing, losing their jobs, and we don't address those

needs

, they won't have any foundation on which to build a recovery. The last part is I want to offer some good news. Statistics show that most people are getting better.

Remember the CDC, if we go from 15% of people who have had COVID for a long time to 6% still have it. That suggests that 60% of people have improved. And so, most of that healing, in my experience, happens within the first year or two and a half years. And even people who don't fully recover in that time are certainly getting better. And that's why time is a healer for most people. And really managing your long COVID symptoms by controlling that energy, without hitting that wall of post-exertional malaise, doing some intentional rehab or symptomatic treatment can be really beneficial in managing symptoms.

While all researchers around the world are trying to find a curative treatment and therefore the research is preliminary, I believe we are making progress and we are also seeing many patients getting better. So thank you very much for listening.