Half of people awaiting admission to hospital from emergency departments around the country have the flu.
The HSE says that the flu virus arrived four weeks earlier than usual this year and the Minister for Health said this is putting "significant pressure" on the health service.
Simon Harris said that the numbers presenting with the flu-like symptoms means healthcare staff are under pressure to isolate the patients in order to prevent the spread of the virus through the hospitals.
He said that this "slows down patient flow".
A meeting of the HSE Winter Oversight Group heard that so far this flu season, 18 people have died as a result of the virus, while that number is around 100 for the whole of 2019.
This is despite what Dr Kevin Kelleher, Assistant National Director of Health Protection at the HSE described as an "amazing" increase in the uptake of the flu vaccination.
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Dr Kelleher said that the number of vaccinations is "higher than ever" and has increased by 50% in the last three or four years.
He said uptake among the over 65s and healthcare workers is also increasing.
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This morning there were 187 patients on trolleys in Emergency Departments around the country, and 84 of those were in need of isolation due to flu.
Not all of those attending with flu or flu-like symptoms will be admitted to hospital, however Dr Kellher said that most of those who are actually admitted with other conditions.
The HSE says the flu virus may already have peaked but could stay active for another five weeks.
The vast majority of people with flu should be able to look after themselves at home rather than going to their GP or to hospital.
Dr Vida Hamilton, National Clinical Adviser to the HSE, says that bed rest, simple over the counter remedies and lots of fluids should help most people.
She said the flu is at its worst between day five and day seven, and that after that people should start to feel better.
Dr Hamilton said that if you can hold a normal conversation, make sense, and go to the bathroom yourself, you are doing alright.
However, she warned that if you have additional conditions, are confused, agitated, are unable to complete a sentence without getting breathless or are not going to the toilet, then you should see a doctor.
The meeting also heard that the number of people attending Emergency Departments in our hospitals is up by 2.5% since November 2018.
More than half of patients are seen within 6 hours while, 95% of patients are seen in a 24 hour window.
As of this morning, 113,059 people waited on trolleys this year, a 13.6% increase on the same period last year.
