Extreme fatigue, brain fog, breathlessness: more and more people are suffering from the effects of what has come to be known as "long COVID".
Simone Ravera, a 50-year-old nurse, says she is still struggling with long-term effects of COVID-19, with her symptoms - constantly feeling tired, breathless and unable to concentrate - turning her life completely upside-down.
The symptoms came four months after she was first infected with the virus.
It was "nearly as bad as in the beginning. And it's completely clear that you can't function normally, or think normally, not really able to manage your daily [life]," Ravera told AP.
"What really slows you down in this weak position is feeling like a stranger in your own body. You also feel depressed because you don't know what the future will look like, whether this is ever going to end. It's scary."
That is how she ended up in Germany's Heiligendamm, rolling up her trousers and taking off her shoes before carefully stepping into the cool waters of the Baltic Sea for some light exercise.
A rehabilitation clinic in the area specialises in helping people with lung diseases such as asthma, chronic bronchitis and cancer.
In the past year, it has become a major rehabilitation centre for COVID-19 patients, with at least 600 people from all over the country seeking treatment at the facility since the pandemic began.
Symptoms can resemble dementia
Some of the patients who have relied on the facility were close to death and have had to learn to breathe properly again, rebuild their stamina and overcome a range of neurological problems.
Some patients had mild to moderate initial symptoms and now suffer from distressing rebound symptoms, such as extreme fatigue and memory lapses.
"It begins with an inability to find the right words, difficulty concentrating, and symptoms of dementia," explains Jördis Frommhold, head physician at the rehab clinic.
"There was a nurse, for example, who used to work in dialysis who suddenly found herself in her flooded kitchen because she forgot to turn the water off," she added.
"Then there are patients who discover bread they baked in their bread-making machine days later. And these are young patients who have never had neurological problems before."
'Those who are otherwise never ill'
Most of the patients are between 18 and 50-years-old and had no pre-existing illnesses.
"They're the ones that are usually never ill," explains Frommhold.
At the rehabilitation clinic in Heiligendamm, they can regain their strength - and learn how to deal with the symptoms in everyday life. But it's a big challenge when some say their symptoms aren't recognised.
"Unfortunately, there was a period in between when everything was almost normal and then the symptoms came back. Many of these patients are not taken seriously, there is hardly any acceptance of these forms of long-COVID symptoms so that these patients have to go through a veritable odyssey of visits to doctors," she said.
'You don't trust your own body anymore'
This is the case with Heike Risch, a 51-year-old kindergarten teacher, who could hardly walk after being discharged from the hospital.
To this day, the smallest tasks are difficult for her - even reading the time on a clock.
"I felt like I’d aged 30 years in a short period of time," says Risch. "When I would take a shower, I would just go in and out and afterward I had to just lie down and take a nap."
"You don’t trust your own body anymore. You don’t trust your own head anymore," she added.
Still, she hopes to return to work one day. She enjoys working with children, but has a lot of responsibility in her job. "You need to be able to do two things at once."
'The disease comes in waves'
Ravera also finds it hard to imagine returning to working multiple shifts at the hospital. She says she doesn't know when she will be completely well again. "The illness comes in waves," she says.
Instead, Ravera is considering using what she learned in rehab to help others suffering from COVID's long-term effects. "It's a bit of a journey into the unknown," she said.
Many are calling for more understanding, education and money for research into long COVID. Until then, it is unclear how long the impacts of the disease will continue to shape their lives.