A specialist in infectious diseases has warned that people could suffer from the impact of having Covid-19 for years, with many experiencing prolonged symptoms.
Professor Sam McConkey, associate professor and head of the Department of International Health and Tropical Medicine at the Royal College of Surgeons in Ireland (RCSI), said some patients continue to have "significant dysfunction" of the lungs, heart or brain up to three or six months later.
Those recovering from Covid-19 have reported feeling faster heart rates than usual, others suffer panic attacks, while some say they cannot walk as far and some have reported having "brain fog" and difficulty concentrating.
Professor McConkey, who is also a consultant in general medicine, tropical medicine and infectious diseases at Beaumont Hospital in Dublin and Our Lady of Lourdes Hospital in Drogheda, said patients are anxious about the future.
The professor and his colleagues at Beaumont Hospital are leading a wide-ranging study into the impact of coronavirus on patients.
Around 200 people previously diagnosed with Covid-19 are being assessed.
Those involved in the study include respiratory specialists, heart specialists, specialists in haematology, intensive care doctors, as well as psychiatrists and psychologists.
The study is expected to last another five months.
Professor McConkey said: "We started with the sickest ones who were in Beaumont intensive care and those sick enough to need hospitalisation. We have got a team of staff who are calling them on the phone with a checklist and asking them about their symptoms.
"If the patients identify they have any ongoing symptoms, we get them in for a chest X-ray and they go through a full suite of diagnostic tests and a psychological assessment.
"Some people are having a lot of anxiety and depression and psychological symptoms after Covid-19, especially those who were in ICU.
"The study is still ongoing so there are no results, though there are clearly some people who had Covid-19 who do have significant dysfunction of the lungs, heart or brain three or six months later."
The professor said that although the long-term outcome of Covid-19 remains unclear, there is a possibility some patients may have symptoms for years.
"Some people are feeling physical symptoms where they just can't walk more than 100 yards and they are anxious as they want to know what is the future and fear they won't get better," he added.
"They are very rightly concerned about their physical function. There's a worry that this seems to exist as a feature.
"We are still in the investigation stage, it looks like it's not just the same as COPD or pulmonary fibrosis and that it's something different.
"That's my anecdotal experience of meeting people who have had Covid-19."
There are also concerns about the psychological impact on young people admitted to hospital with Covid-19, particularly those admitted to ICU.
"There are people who never really realised in their life, up to that point, that human life and human existence has a finite end and that one of the few things all of us can be completely certain about is that we will die," he added.
"Being confronted with that through a potentially fatal disease is really shocking for some people as they have not worked through that before."