Heather-Elizabeth Brown feels grateful to have survived her bout with severe COVID-19. But more than two years after testing positive for the virus, she is still managing the physical and mental toll.
After contracting COVID-19 early in the pandemic and subsequently going on a ventilator for a month, she faced significant health challenges, from rehabilitation to chronic conditions including diabetes.
"COVID has taken a lot from me," Brown, 37, a corporate training consultant in Detroit who is a COVID long hauler, told "Good Morning America." "I took for granted how much I was just 'go, go go' before I became ill in April 2020."
Doctors have made progress in treating people with lingering COVID-19 symptoms, though there is still much to still learn about who experiences it and why. With no test for long COVID, it also can be difficult to diagnose.
Studies so far estimate as many as 13% to 30% of people who get COVID-19 may later develop long COVID, which commonly include fatigue, shortness of breath and "brain fog" for weeks, months or, as in Brown's case, years after the initial infection.
"I would be lying if I said that my life wasn't irrevocably changed by this whole experience," Brown said.
MORE: 'Unthinkable tragedy': U.S. COVID-19 death toll surpasses 1 millionBrown first started showing symptoms in April 2020, though tested negative for COVID-19 twice, she said.
"I was starting to have trouble breathing," she said. "I was so tired. I was barely able to perform basic functions to take care of myself."
As her systems worsened, she went to the emergency department three times before she was admitted with symptoms including an elevated temperature.
An X-ray showed that Brown -- who eventually tested positive for COVID -- had COVID-induced pneumonia in both lungs, and she was put on the "highest level of oxygen," she said.
Within two days of being admitted, doctors told her that her lungs were failing. She was put into a medically-induced coma and placed on a ventilator on April 18, 2020, she said. She remained on the ventilator for 31 days.
"It was an experience that I don't think I can explain adequately," Brown said. "I had a lot of vivid dreams and nightmares."
MORE: Inside 28-year-old's nearly 2-year battle with long COVIDWhen she woke up, she wasn't able to talk due to a breathing tube and wasn't able to walk.
"The whole left side of my body was so weak, I couldn't even hit the call button for the nurses," she said.
Due to COVID-19 protocols, she wasn't allowed to see anyone beside the hospital staff.
"I was able to FaceTime with my mother but no one was able to visit me in the hospital," she said.
For patients who have been on ventilators for a prolonged period of time, it's common to use medications that may cause severe muscle weakness, according to Dr. Annas Aljassem, director of functional pain and rehabilitation at Beaumont Hospital in Royal Oak, who treated Brown.
"A lot of their post-recovery is retraining muscles," he told "Good Morning America." "On top of that, a lot of these long haulers will have debilitated lungs."
That can translate to a "prolonged recovery time for the things that we take for granted, day-to-day kind of things," Aljassem said.
You never think at 35 that you'll be re-learning something so basic that we take for granted as walking
Brown said she went to rehabilitation for about seven weeks due to her prolonged ICU stay, and has gone through months of physical therapy, pulmonary therapy and occupational therapy.
"You never think at 35 that you'll be re-learning something so basic that we take for granted as walking," she said.
Brown said she had to use a home healthcare company to help her do things around the home.
"I still walk with a limp. I'm still working on tackling the stairs, standing for long periods of time," she said. "I haven’t started walking again in high heels yet but that's on my list of things to do and I'm committed to that."
In addition to recovering from an extensive ICU stay, Brown also now manages diabetes and high blood pressure -- two health conditions she didn't have before getting COVID-19.
"For a while, I was on a lot of insulin, but since I've been able to get it more managed," she said of her diabetes.
Research has found that COVID-19 survivors are at an increased risk of being newly diagnosed with diabetes up to one year after recovering. There are several theories for why, though the exact cause has not yet been determined.
Brown said she has also had issues with nerve pain and brain fog, though the latter has gotten "infinitely better."
MORE: What’s behind lingering COVID brain fog?Common long COVID symptoms include severe fatigue and impacts to thinking and breathing weeks or months after the initial infection, according to Dr. Jason Maley, the director of the Beth Israel Deaconess Medical Center's Critical Illness and COVID-19 Survivorship Program and an assistant professor of medicine at Harvard Medical School.
For cognitive impacts, "We approach it in many ways similar to how we try to help patients who have had traumatic brain injury or concussion recover, because we see a lot of overlap in the symptoms and the ways it's affecting people's brain function," Maley said.
Those experiencing fatigue may experience what's known as post-exertional malaise, he said.
"They feel physical illness and worsening of all of their symptoms as a result of trying to be physically active, even if it's just mild activity around the house," Maley said. "That's been described in other post-acute infectious illnesses prior to COVID-19."
Other patients may be fatigued and weak due to an ICU stay and need to rebuild their muscles.
"That takes time and that's really a more intensive rehab approach," he said.
Long COVID has also been a mental struggle for Brown, as she's often wondered, "Why me?" and has been frustrated by her extensive recovery. She said she also has post-traumatic stress disorder from her ICU experience.
"I want a normal week where I'm not constantly reminded in some way, shape or form of COVID. Of the struggle that I've had with COVID and the trauma that I've endured," she said.
A study led by Maley that was published last month in Critical Care Explorations, the peer-reviewed journal of the Society of Critical Care Medicine, found that "significant symptoms" of post-traumatic stress were found in one-third of ventilated patients six months after they were discharged from the hospital.
Aljassem said he has seen COVID long haulers experience mental trauma from the prolonged isolation they experienced during their treatment and subsequent rehab.
"Mentally they may be in a place and physically their bodies are in another place," he said. "Processing that mentally is a very important piece of your recovery."
Maley said long haulers also may experience trauma if their illness is not recognized by their healthcare provider.
"It's clear to us this is a real illness and there's a lot of mounting scientific studies about this, but it doesn't always show up easily on an X-ray, or it's not showing up on a simple blood test," he said. "When you can't think straight and you're exhausted all day and you were previously perfectly healthy before this, it's really traumatizing to be searching for answers and have people largely ignoring you."
As she continues to battle COVID-19 symptoms, Brown said she is "getting back to the best parts of me" before she got sick. Part of that involves her faith.
"I definitely feel like my faith has been strengthened," said Brown, who is a minister at her church. "I feel like I've gotten confirmation of the things that I was believing and professing in faith but then to have a moment to see it manifest in real life is much different."
Seeing a therapist trained in PTSD has also helped Brown process the trauma she experienced and be patient in her healing journey, she said.
"She said you've been through so much, you have to be kind and you have to learn how to make sure that you're gentle with yourself," Brown said. "Something I had to remember and honor -- I am still on a healing journey, and every day is not the same."
Aljassem said that compared to where Brown is now versus when he first met her is "miraculous."
"There's always that discrepancy in how you view yourself, especially in how your healthcare team is viewing you," he said. "I try to reinforce to her specifically on focusing on those little victories every day and not so much what I can't do anymore."
MORE: COVID long-hauler marks 2 years grappling with 'bewildering array' of agonizing symptomsBrown has also devoted much of her time and emotional energy to long-hauler advocacy and being a voice for the community. She is involved with several support and advocacy groups for COVID-19 survivors, including the Body Politic Covid-19 Support Group and the COVID-19 Longhauler Advocacy Project.
"I am a fierce advocate for the COVID-19 long hauler community and for people who have survived this, and for families who are dealing with it in any capacity," she said. "I take seriously the position I've been given to be able to just encourage people and to let people know that even though it can be difficult and even though it can be scary it's definitely something that people can overcome."
She does feel that there's a lot more work to be done for the community and in understanding long COVID.
"[We're] keeping our feet on the gas when it comes to research and when it comes to education and when it comes to really being vocal proponents for people who have been affected by COVID," she said.
As more is learned about long COVID, doctors may be able to implement better strategies in treatment, Aljassem said.
"It's tough to develop treatments without understanding disease, but at the same time, we as clinicians … feel the need and pressure to find things that will help people feel better," Maley said.
Brown said it continues to be a challenge comparing herself to who she was before COVID-19, but that being a long hauler has made her more resilient and kinder to herself.
"I'm still thankful and I'm still grateful for my life," she said. "I'm hopeful for my future but I just realized that I have to take it one day at a time."
ABC News' Asher May-Corsini and Lauren Sher contributed to this report.
