The road to recovery after serious COVID-19 is long. Some may never be the same.

Veronica Alexander came to physical therapy in a wheelchair on a recent afternoon wearing a bright red dress and a blue mask that covered the oxygen tube she still needed nearly two months after her coronavirus symptoms began in June.

She didn’t remember the month she spent in Temple University Hospital, where she was on a ventilator for weeks. After that, she needed a month of therapy at PowerBack Rehabilitation in Center City before she could go home.

Her physical therapist, Tram Tran, started with the toughest exercise: climbing a portable staircase with three stairs.

When she arrived at PowerBack, Alexander, 61, could stand for only three seconds before her legs buckled and she collapsed in a chair. On this August day, with Tran near for support, she walked to the stairs, climbed one at a time as instructed and returned to the chair. That was enough to make Alexander’s heart rate shoot to 135 beats per minute, what many people would see after a jog. Normal is 60 to 100, Tran said. Her blood oxygen, meanwhile, had plummeted to 80. Anything below 90 is too low.

The numbers rose and fell again and again as Alexander tossed a ball to Emily Trott, a rehabilitation technician, and walked about 50 feet a couple of times. This was an achievement for a woman who arrived terrified that she might never walk again. She still wonders if she’ll be able to use her hands and arms normally someday. Her shoulders were injured while she lay on her stomach in the intensive care unit, a process called proning that improves breathing in COVID-19 patients.

Alexander, who was disabled by arthritis before she got sick, was only a few days from returning to her North Philadelphia apartment, but she was nowhere near her pre-COVID self. No one knows whether she ever will be.

“I think that most people kind of understand that this is a brand-new illness, a brand-new phenomenon, that we’re dealing with, and we’re just doing the best that we can,” said Jason Pan, a Penn Medicine physiatrist, a doctor who specializes in rehabilitation. Penn recently created a clinic for COVID patients who need post-hospital follow-up. He said patients will probably make most of their gains in the first year after their illness, but he can’t tell them how much they’re likely to recover.

Videos of joyful send-offs as COVID-19 survivors leave hospitals are a staple of TV news and social media. But they don’t hint at what comes next.

“There’s a great deal of celebration that occurs when people are leaving the hospital, and for good reason, but the journey to recovery still has a long way to go,” said Reg Blaber, chief clinical officer for Virtua Health. “This virus is just so evil. It wreaks so much havoc.”

Long before COVID, doctors knew that patients who needed intensive care were at high risk for long-term physical, cognitive, and mental health problems, a condition that was named post-intensive care syndrome (PICS) in 2012. Survivors of acute respiratory distress syndrome (ARDS), a severe form of lung infection that is often the reason people with diseases like COVID-19 need a ventilator, were especially likely to struggle.

» READ MORE: When coronavirus kills, ARDS can be the culprit. Here's what you need to know.

Dale Needham, a critical-care physician at Johns Hopkins University, has been studying how patients fare after ICU stays and ARDS for more than 17 years. Up to 70% of ARDS patients, he said, still have severe fatigue six months to a year after hospital discharge. A year after an ICU stay, a third of people who were working before they got sick are jobless. Joint problems and muscle weakness can last for months or years. A third of survivors of respiratory failure or shock have cognitive impairment a year later. Anxiety, depression, and post-traumatic stress disorder are common years later in people who have had an ICU stay regardless of how sick they were.

» READ MORE: A new frontier in ICU research: Post-intensive care syndrome

Surprisingly, chronic lung problems have not been an issue in past ICU survivors. “Patients come into the ICU for ‘lung failure’ but go home with long-lasting problems with their thinking, their mood, and their muscles,” Needham said. “These problems can be less obvious as a consequence of ARDS and get easily overlooked.”

The coronavirus, Needham said, has led to a huge increase in ARDS, so some health professionals are seeing such patients for the first time. They may not know, for example, that hair loss is a common reaction to the physical stress of severe illness, or that steep changes in heart rate and oxygen levels with minimal activity occurred in ARDS patients before the coronavirus.

But coronavirus patients could be worse off than others with PICS. Many had especially severe lung complications and spent an unusually long time on ventilators, heavily sedated and immobilized. Unlike typical ARDS patients, fear of contagion deprived them of physical therapy in the hospital and even family visits, which often calm and motivate patients, Needham said.

Doctors are also seeing what some have dubbed “long haulers,” patients whose symptoms persist even after relatively minor illness. Mount Sinai Hospital in New York opened a clinic for such patients. Most were never hospitalized yet are still dealing with shortness of breath, chest pain, weakness, fatigue, and difficulty concentrating, said Zijian Chen, an endocrinologist who is the clinic’s medical director. In some cases, imaging and blood tests tell doctors the patients have organic damage. In others, there is no explanation yet for the lasting symptoms.

Acute rehabilitation facilities like PowerBack, Magee Rehabilitation Hospital, and MossRehab at Elkins Park opened units specifically for COVID-19 patients who couldn’t leave the hospital for home.

Therapists and doctors said these patients are sicker and stay longer than similar patients they saw before COVID. Some patients still test positive when they arrive and must be treated very carefully to keep staff safe. Many receive therapy in their rooms, which calls for portable equipment and creativity.

Some patients have arrived with unusual pressure ulcers on their faces and knees as a result of proning. One doctor had a patient who needed plastic surgery. Some have survived clots in their lungs or other organs. Amputations are a hazard of serious COVID-19.

Therapists and doctors have been struck by how many coronavirus survivors have trouble with memory or organizational ability. Brian Kucer, a Magee physiatrist, said patients often feel foggy and overwhelmed. “It’s not particularly different from how people feel after having a concussion,” he said.

Emotional problems are common. “One thing that stands out is they’re all depressed,” said Paula Bonsall, a Magee occupational therapist. “They’re all isolated, and they’re all anxious.”

The first rehab priority, though, is usually muscle weakness and endurance. Some new patients can’t sit on the edge of a bed for more than 30 seconds. Norma Sampson, 77, who stayed at PowerBack from April 23 to June 12, discovered that she couldn’t move a blanket from her lap to the foot of the bed. “It seemed so heavy,” she said. Kucer said he’s seen patients who were so exhausted after putting on a shirt that they needed to sleep the rest of the day.

This weakness largely stems from weeks of lying in bed. Patients can lose up to half their muscle mass, Kucer said, adding that doctors estimate that patients need three or four days of therapy for every day of bed rest.

Therapists have to very slowly help patients build muscle strength while monitoring heart rates and oxygen frequently. The goal often is making patients strong enough to walk, sit on a toilet, and climb stairs when they go home.

Wearing protective gear makes it harder for therapists to form a strong bond. Hallie Zeleznik, a physical therapist at University of Pittsburgh Medical Center, has learned to talk more. “I know you can’t tell, but I am smiling so big for you now,” she’ll say, “or I know you can’t tell, but I am so sorry you’re feeling this way.”

Doctors and therapists are confident that many patients will return to normal. “I think a lot of them are going to get close enough to where they don’t notice a huge difference,” Kucer said.

Robert Andersen, 66, who lives in ManorCare Health Services in Montgomeryville, got treatment there when he had COVID-19. When he started therapy there in April he had trouble going from his bed to a chair and his balance was off. He had lung disease and had had a stroke before he got the coronavirus. By late July, he felt normal even though he was still easily winded, possibly because of the earlier lung damage. The illness itself felt unreal. “Sometime it feels like getting COVID, it’s like a bad dream almost,” he said.

Norma Sampson, who spent a month at Thomas Jefferson University with COVID-19 that led to a mild stroke, insisted on walking the two blocks home when she left PowerBack in June. Members of her therapy team accompanied her. She made it — with four rest stops. She was plagued by “really dark” dreams for weeks but is doing well now, even doing her own grocery shopping. She recently walked 10 blocks from her doctor’s office to her apartment. “I’m close to 100% now, I think,” she said. “Believe me, it was a long road.”

Virginia Hamilton, 63, of West Oak Lane, said she spent four or five days on a ventilator at Einstein Medical Center Philadelphia before transferring to MossRehab for 16 days. She needed help walking and her voice was “fuzzy” and “squeaky” from the breathing tube. She got speech therapy and used bikes that strengthened her arms and legs. By June 2, she was back at work as a peer counselor at Friends Hospital, a job that requires a lot of walking. She’s riding the bus again and caring for her father, who has dementia. She still coughs occasionally, but feels normal. And very grateful. “It’s like I got a renewed lift on life, a second chance, you could say,” she said.

Alexander, who was on disability before she got sick but could walk two blocks on her own with a cane, is in the early days of recovery.

Once she started breathing on her own, she realized how weak she was. “I was devastated, because I thought I would never walk,” she said.

Tran saw how anxious her new patient was. “I just looked at her and I said, ‘You will be able to walk again. Trust me.’ ”

The next week, Alexander walked 25 feet across the room while Tran followed behind with her wheelchair. They both cried, although Tran hid her tears because she thought they were unprofessional. “I thank God and I thank Tram. I get emotional about it,” Alexander said. She is still upset that all her efforts to avoid the virus failed. “I realize now nobody is safe.”

She is still worried about her arms. She can’t use her right hand and four fingers on the left are numb. A doctor told her that surgery could help. “I might not never get the strength back in my arm,” she said, “but I thank God that I’m still here.”

Tran doesn’t know how her patients will feel in a year or two, but Alexander’s progress makes her feel good. “It’s very rewarding as a therapist,” she said, “just seeing her ability to hope again.”