A consultant respiratory physician at Beaumont Hospital has said that about half of the people they see in their post-Covid-19 clinic are doing well and feeling better.
But Dr Killian Hurley said the other half have persistent symptoms, including breathlessness, cough and severe fatigue.
Patients are usually seen three to four months after they first contract the illness.
Dr Hurley said that with severe Covid patients who were admitted to hospital, the virus can affect organs, including the lungs and heart, as well as muscles and the brain.
People with severe Covid-19 who were admitted to intensive care also have psychological impacts and problems with their memory and cognition.
Dr Hurley said they are seeing a number of patients left with scarring or fibrosis on the lungs, and a small number who have scarring or inflammation of the heart, due to myocarditis, following Covid-19.
He added that this is only a small number of patients, but it is something they are concerned about.
There is a follow-up service in Beaumont to assess patients who have had Covid-19, but Dr Hurley said there needs to be a coordinated national approach, so that patients who may be affected can be identified and referred to specialists.
Experience with SARS 1, MERS and H1N1 Swine flu shows most people were better at one year, he said, adding that those with persistent symptoms were better at five years.
Dr Hurley said only a very small number of people had long term consequences with those viral infections.
He said Covid-19 is entirely new, but they think most people will get better.
However, he added that they do need a system to follow up patients that are at risk of complications.
Dr Hurley said it's surprising that these symptoms do persist for a long time, but he things they can be reassured that most people do get better.
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