Everything We Know About Long-Haul COVID

It seems that nowadays, everyone has had (or knows someone infected with) COVID-19. While most recover from infection, there is a growing number of people reporting symptoms long after the virus is gone from their system. "We're seeing a spectrum of symptoms after acute COVID-19, some of which would be expected after other critical illnesses. Some are minor, but other people may need continuing care and even readmission to the hospital," Dr. Emily Brigham, MPH, a lung disease and critical care specialist, told John Hopkins Medicine.

In the early days of the pandemic, a 2020 study published in JAMA reported about 35% of patients who recovered from symptomatic COVID-19 infection had lingering symptoms for over 2 weeks. Nowadays, the Centers for Disease Control and Prevention (CDC) says people with mild illness can also experience long COVID. A person is defined as having long COVID when new or ongoing symptoms last for four or more weeks. Scientists are still trying to understand the extent of damage SARS-CoV-2 (the virus that causes COVID-19 infection) causes in the body, as well as what risk factors make people more susceptible to getting it before infection. 

Fortunately, research has uncovered some common symptoms of long COVID. Government officials are also enacting changes to help people with long COVID cope with impairments to their life. Here's what scientists currently know about long-haul COVID.

Symptoms from long COVID vary. Some people experience shortness of breath, for instance, while others have memory problems. One way or another, long COVID incurs physical and mental impairments that can significantly impact people's day-to-day activities. For this reason, the U.S. Department of Health & Human Services officially recognizes long COVID as a disability. People with long COVID are eligible to apply for disabilities and approved on a case-by-case basis. If approved, it entitles them to accommodations from school, businesses, and governments such as providing refuel assistance or the use of a service animal if necessary.

According to CNBC, hiring a lawyer familiar with disability applications can maximize your chances of getting benefits. It's also important to apply early because getting legal representation and the application process itself can take months. "Many — particularly those without legal representation — end up wrongfully denied on multiple occasions before finally being approved with a lawyer's help," said Rebecca Vallas, a senior fellow at the Century Foundation. "Untold numbers spend what savings they have to try to stay afloat while waiting for an appeal to be heard — and countless more lose their homes in the process." 

Also, keep in mind the financial restrictions, as only people who are not working, are not able to work for at least a year, paid FICA taxes for 10 years, and have your income fall below $1,310 per month are eligible for disabilities.

Because SARS-CoV-2 can target multiple organs, long COVID symptoms may arise from lasting damage in these areas. In a 2021 study published in The Lancet, researchers found that almost 70% of people who "recovered" from COVID-19 and discharged from the hospital continued to show at least one COVID-related symptom (fatigue or muscle weakness).

There is currently no clear timeline on when people's long COVID symptoms resolve. Data from the Zoe COVID study found that 1 in 10 people continue showing symptoms for over 3 weeks. Meanwhile, a December 2021 study published in the American Journal of Physical Medicine & Rehabilitation found that long COVID symptoms can last for at least a year. "This study is a concerning reminder of how severely debilitating PACS symptoms are, the toll they take on health and wellness, and the fact that, without active treatment, these symptoms appear to persist indefinitely," Dr. David Putrino, Director of Rehabilitation Innovation for the Mount Sinai Health System and senior author of the study, told Mount Sinai. His research also found that the most common long COVID symptoms were fatigue, brain fog, and headaches. Additionally, physical exertion, stress, dehydration, and weather changes made symptoms worse.

While some long COVID symptoms disappear after a few months, others are for life. More research is linking long COVID to diabetes. A 2022 CDC study found the risk of developing diabetes a month after recovering from COVID-19 infection increased by 166%.

Per the Ohio State University, there are possible but still unproven reasons for this. Prior research shows the immune system produces all types of antibodies in response to infections, including ones that target pancreatic cells involved in making insulin. Attacks on the pancreas lead to a drop in insulin-producing beta cells. Insufficient insulin ushers high blood sugar levels (acute hyperglycemia). After recovering from the illness, the body enters a glucose-regulation "honeymoon" period where the glucose-regulation is out of whack and the pancreas only needs to make a small amount of insulin. This may last up to a decade. After the phase ends, adults find their bodies needing more insulin than their pancreas is making, requiring daily insulin doses.

If a person was prediabetic, high-dose steroid treatment for COVID-19 illness and acute inflammation could have increased insulin resistance and elevated glucose to higher than normal levels. A 2021 study published in the journal Cell Metabolism found that insulin resistance in severe COVID-19 cases was the main cause for later development of high blood sugar. COVID-19 infection causes defective fat cells, impairing the production of adiponectin, a hormone needed to sensitize cells to insulin and protects against insulin resistance.

People with long COVID may experience sustained lung damage, according to John Hopkins Medicine. The amount of damage endured in the lungs influences the severity of symptoms in people with long COVID. Mild to moderate lung complications include shortness of breath and pneumonia. Most COVID cases involving pneumonia are severe and may cause people to have trouble breathing for months. In severe long COVID cases, lung complications can develop into life-threatening conditions such as acute respiratory distress syndrome or sepsis. 

It's still a mystery why SARS-CoV-2 causes lung-related long COVID symptoms in some people but not others. However, scientists from the University of Michigan are trying to find the answer. After looking at lung biopsies from people with ongoing respiratory symptoms after recovering from COVID-19 illness, they found that most lung damage came from a preexisting lung disease. Most patients in their study had signs of usual interstitial pneumonia (UIP), a chronic lung disease that causes stiffness and scarring of the lungs. 

"We were seeing a lot of UIP, which isn't the pattern we tend to associate with acute lung injury," Dr. Kristine E. Konopka, associate professor of thoracic pathology and lead author of the study told the University of Michigan. "So, we think these are patients who had lung disease prior to COVID and maybe they just weren't being followed by primary care physicians. They then had COVID, are still sick, and their UIP is finally being picked up."

While SARS-CoV-2 was initially believed to be a respiratory infection, scientists now know that it can directly or indirectly affect the brain. "This is a systemic illness and it affects many parts of the body. The brain fog — or really I would call it difficulty concentrating and difficulty thinking — is something that is described in a number of different viral infections," Dr. Davidson Hamer, an infectious disease expert and Professor of Global Health and Medicine at the Boston University School of Public Health and School of Medicine, told NBC Boston. "And it may persist for weeks and that's definitely been a challenge for people who have long COVID."

Per the National Institute of Neurological Disorders and Stroke (NINDS), most people infected with SARS-CoV-2 with neurological symptoms develop dizziness, headaches, muscle aches, and changes to taste and smell. A 2021 study published in Annals of Clinical and Translational Neurology found that people with neurological complications after recovery were more likely to report cases of brain fog and headaches. For people who required intensive care during their infection, more severe neurological complications such as muscular weakness, nerve injury, and pain syndromes may emerge. With insufficient oxygen, permanent brain damage is likely. 

On rare but serious occasions, SARS-CoV-2 can induce seizures, blood clotting in the brain, and stroke. Inflammation or a lack of oxygen in the brain from SARS-CoV-2 may affect neuronal communication between different brain areas, a condition called diffuse white matter disease (per NINDS).

A common neurological symptom experienced by people who develop COVID-19 infection is a loss of smell and taste. 

While most people recover their senses, a small minority remains impaired. According to the National Institute of Neurological Disorders and Stroke (NINDS), people lose their senses because SARS-CoV-2 damages nerve cells involved in detecting smells or the sensation of flavors and sending that information to the brain. Repairing damage to these cells requires replacing them with new ones, and these can take a few weeks or months. 

A November 2021 article published in the journal JAMA found that on average, 700,000 to 1.6 million people lose their sense of smell for 6 months or more. While your body is in the midst of replacing damaged cells with new ones, you might find your sense of smell to be altered, with some odors smelling more unpleasant than usual.

About 15% to 80% of people experience long COVID, according to the American Medical Association. However, not all long COVID experiences are the same — and that is because there are three types of long COVID. 

The first is when SARS-CoV-2 causes direct cell damage and symptoms linger from the sustained damage, making it difficult to recover completely after the virus leaves the body. The second long COVID category involves symptoms coming from a prolonged hospitalization period when a person is bed-bound for several weeks. "There is inherent muscle weakness. There is inherent cognitive brain dysfunction. There is inherent psychosocial stress causing post-traumatic stress disorder-like syndrome, which we call post-ICU care syndrome," Dr. Devang Sanghavi, a critical care doctor from Mayo Clinic, told the American Medical Association. "That is from chronic hospitalization." The third long COVID category involves new symptoms emerging after infection. These arise because of prolonged interactions between the body and the high inflammatory activity produced by the immune system.

Beyond the lungs, SARS-CoV-2 targets and injures the heart. A July 2021 study published in the journal JAMA Network Open had people with long COVID track their symptoms using wearable devices. The results showed low heart rates 9 to 15 days after showing COVID-19 symptoms, and this lasted for almost 2 to 3 months after recovery. 

According to John Hopkins Medicine, SARS-CoV-2 causes cardiovascular damage when it infects heart cells with ACE-2 receptors. The infected cells trigger a response from the immune system, resulting in an increase in inflammation. On its mission to eliminate the virus, a prolonged inflammatory may harm nearby tissue such as the heart. Cardiovascular complications may also arise from blood vessel inflammation in severe COVID-19 cases because damage to vessels and blood clots can obstruct blood flow to and from the heart.

Heart problems during long COVID can have long-term consequences for your health. Research presented at the EuroEcho 2021, a scientific congress for the European Society of Cardiology, found that about a third of people experience shortness of breath during physical activity a year after recovering from COVID-19 infection. These people had no history of heart or lung disease. After looking at their hearts through a cardiac ultrasound, the researchers found abnormal heart rhythms and cardiovascular damage that could explain the breathlessness.

If you're feeling out of breath walking from the kitchen to the bathroom, it may be a sign of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). According to John Hopkins Medicine, about 1 million to 2.5 million people are affected with ME/CFS, and with the COVID-19 pandemic, more people are reporting similar symptoms after recovery. Common symptoms of ME/CFS include severe or debilitating fatigue, trouble sleeping, brain fog, and a flare-up of symptoms after making a physical or cognitive effort to do things.

In an August 2021 review published in the Proceedings of the National Academy of Sciences, researchers suggest that ME/CFS after COVID-19 infection is caused by biological processes that become abnormal after infection. Per the team, increased inflammation in the brain and body, cells' inability to produce ATP, and a redox imbalance — when there is an excessive amount of oxygen in a cell — could lead to symptoms akin to those of ME/CFS. 

"The body's response to infection and injury is complex and covers all body systems," Bindu Diana Paul, PhD, MS, assistant professor of pharmacology and molecular sciences at the Johns Hopkins University School of Medicine and lead study author, told John Hopkins Medicine. "When that response is in disarray — even just one aspect of it — it can cause feelings of being tired, brain fog, pain and other symptoms."

There is currently no cure for long COVID, but there are ways to minimize its effects on your day-to-day activities. 

The British Heart Association has several tips for managing a variety of long COVID symptoms. For fatigue and shortness of breath, they recommend adding more breaks and chunking activities into smaller tasks. They advise gradual increases in exercise even if you feel more tired, and continuing activities even if you feel breathless. This is to prevent your muscles from growing weaker, which can add to further breathlessness in the future. When you start to feel out of breath, they suggest taking short but frequent rests. Flexibility exercises like yoga and strength exercises (such as lifting weights to climbing stairs) are helpful in rebuilding muscle and alleviating joint or muscle pain.

For symptoms of brain fog, the British Heart Association says making frequent notes can help jog your memory. You may also want to keep noise levels to a minimum to avoid distractions and disrupt your thinking process. When setting off to do an activity, make a step-by-step plan and continue referencing it as you go through it. While brain fog might resolve on its own, some people with long COVID continue to experience cognitive impairments. Researchers are working on developing treatments specific for long COVID. One ongoing study involves electrically stimulating the brain to treat brain fog.

Similar to COVID-19 infection, no one is immune to the effects of long COVID. A Zoe study found about 1 in 20 people experience long COVID after recovering from infection. The majority are from older adults, as the risk heightens with age. "It can happen to anyone," Dr. Akiko Iwasaki, professor of immunobiology and molecular, cellular, and developmental biology at the Yale School of Medicine in New Haven, Connecticut, told Everyday Health. "It's really scary to think about healthy young people getting long COVID and no longer being able to think clearly, work, and be productive."

An August 2021 study in The Lancet Child & Adolescent Health finds that older children experienced long COVID symptoms than younger children. About 4.4% of children showed symptoms for at least 4 weeks. The most common symptoms were fatigue, headache, and loss of smell. Less than 2% of children had symptoms for 56 days.

However, recent research suggests that long COVID in children could last for much longer. A December 2021 review published in The Pediatric Infectious Disease Journal finds that most COVID-19 studies with children reported long COVID symptoms for at least 84 days. A separate December 2021 study found almost 60% of symptoms in children lasted 1 to 7 months after getting infected (via The Pediatric Infectious Disease Journal).

A potential effect after recovering from COVID-19 infection is kidney damage. A 2021 study in the Journal of the American Society of Nephrology found that COVID-19 infections, including mild cases, have an increased risk of kidney disease. That said, the risk of impaired kidney function was higher among people hospitalized in the ICU. "Based on our research, we believe that 510,000 of those people who have had COVID-19 may have kidney injury or disease," said Dr. Ziyad Al-Aly, an assistant professor of medicine at Washington University, in a press release.

According to an article published in the journal Nature Reviews Nephrology, SARS-CoV-2 may induce a higher risk of kidney disease because of its direct and indirect methods for causing acute kidney injury. Direct injuries could come from high inflammation around the area or damage to the inner layer of blood vessels. Indirect effects are from medications used to treat COVID-19 infection but are toxic to the kidney, inflammation from the rest of the body, and other diseases.

Postural orthostatic tachycardia syndrome (POTS) is a condition that can arise after recovering from a viral or bacterial infection. According to John Hopkins Medicine, COVID-19 infection may cause POTS-like symptoms such as severe fatigue, increased heart rate, chronic nausea or vomiting, shakiness, and brain fog. POTS happens when the autonomic nervous system — the part of our nervous system in charge of involuntary actions such as breathing, sweating, and blood pressure — starts to go out of whack. POTS symptoms can be debilitating, making it difficult to resume activities before you got sick.

"We are being very careful with regard to diagnosing our patients with POTS, as we know COVID-19 can cause blood clots or scars in the lungs, which can cause similar symptoms as POTS but would require very different treatment," stated Dr. Tae Chung, a neuromuscular specialist, rehabilitation physician, and director of the Johns Hopkins POTS Program. If you are diagnosed with post-COVID POTS, doctors will most likely personalize your treatment based on the severity of the symptoms you exhibit. This can include aggressive hydration, making changes to the diet, and prescribing medication. After several months of treatment, you may undergo physical therapy to strengthen muscles that may have weakened after infection.

The COVID-19 pandemic has been universally traumatizing for those who have lost friends and family or who are paranoid of getting themselves or their loved ones infected. Adding to these worries, people with long COVID experience a higher chance of developing mental health problems after recovery. A 2021 study published in The Lancet Psychiatry found about 33% of people recovering from COVID-19 infection were diagnosed with a neurological or psychiatric condition. For 12% of people, this was their first mental health diagnosis. A separate study published in The Lancet found that 23% of hospitalized patients who recovered from COVID-19 infection went on to develop symptoms of anxiety and depression. Meanwhile, research from 2021 shows that about 10.5% of people develop PTSD 9 weeks after recovering from illness (per European Respiratory Journal).

SARS-CoV-2 is associated with damage to the brain, but new or worsening mental health conditions may also stem from the experience of dealing with the infection rather than the virus itself. For instance, people might find the idea of being close to death traumatic or feel anxiety over the gaps in memories after being intubated in the hospital for weeks. "It's helping them deal with that loss of time, and how their body and mind are both recovering from what they've just been through," Caitlin LaGrotte, PsyD, MEd, a clinical health psychologist and assistant professor of medicine at Cooper Medical School of Rowan University, told the American Psychological Association.

If you or someone you know is struggling with mental health, please contact the Crisis Text Line by texting HOME to 741741, call the National Alliance on Mental Illness helpline at 1-800-950-NAMI (6264), or visit the National Institute of Mental Health website.