Video report by ITV News Health Editor Emily Morgan
Words by ITV News Multimedia Producer Suzanne Elliott
Until recently, the Covid-19 narrative was a binary one: it either kills you or it affects you like a bad bout of flu and you'll get over with a bit of rest.
But as the world enters its eighth month living alongside this disease, it is becoming apparent that it is far more complex than that and that in some cases, devastatingly persistent.
The effects of Long Covid, as it has become known (although this is not a medical term), are far reaching - with a vast array of symptoms encompassing both physical and neurological - that drag into weeks and often months.
Most people with Covid-19 who did not require ICU treatment are better within three weeks.
But a study by King's College London found an estimated 10% of people with the virus take at least three weeks to recover, with 250,000 people in the UK alone thought to experience symptoms for 30 days or more.
Many of those experiencing long tail coronavirus were fit, active people whose lives have been completely turned upside down by the ongoing symptoms.
What do we know about Long Covid, how is it affecting people and is there help for those who need it?
What are the symptoms?
Sufferers are reporting a huge spectrum of problems, including severe fatigue, breathlessness, muscle aches, joint pain, 'brain fog,' memory loss, a lack of concentration, as well as depression and mental health problems.
Hair loss has even been reported among some 'long haulers'.
What do we know?
One thing medical experts and scientists do know is there are a lot of unknowns about Long Covid.
As with the acute stage of the disease, the long term symptoms are still far from being fully understood.
A major UK research study into the long-term health impacts of Covid-19 on patients who were hospitalised is being carried out at the University of Leicester and the University Hospitals of Leicester NHS Trust.
The PHOSP-COVID study is the largest of its kind in the world and encompasses many medical disciplines that reflect the range of symptoms seen in Long Covid patients.
Dr Rachael Evans, a Consultant Respiratory Physician at University of Leicester, Glenfield Hospital, is among the team of experts trying to understand, in her words, “what's driving those symptoms, what's causing them and what can we do about them”.
ITV News Health Editor Emily Morgan on the debilitating symptoms many endure for weeks and months from prolonged Covid 19
Dr Evans told ITV News they are seeing "a really big spectrum of recovery rates" from Covid-19.
"We want to find out, what is it about those people that are developing long term symptoms versus those that seem to get better very quickly.”
There are several strands to the study, but in essence, Dr Evans says: “We really hope we'll be able to understand more and really be able to help.
"There are working groups around the lungs, around the heart, around the kidneys, around mental health, around immunology, around the genetics so we really are this sort of collaboration of lots of different specialists, all trying to work out why these symptoms and long time conditions are developing and why in certain people," she said.
Dr Evans said the team, led by Chris Brightling, Professor of Respiratory Medicine, are "definitely seeing a good proportion of people" with ongoing symptoms such as fatigue, breathlessness and problems with concentration.
And while older ‘long-haulers’ are struggling with worsening memories post-virus, Dr Evans says young people are also suffering from what is often described as "brain fog".
"People feel very different to the way that they're able to think and process things compared to before (they had) Covid.”
They are also seeing a proportion of people that have higher levels of anxiety and depression.
"Some of that might be as a reaction to having been terribly unwell with a condition that other people have died from, that will always have an impact.
“But we don't know whether the virus itself has a neurological impact that will then cause symptoms of anxiety and depression," Dr Evans explains.
A separate study found that in as many as half of patients, even those who were not hospitalised, Covid-19 had a damaging effect on the body's key organs.The study by COVERSCAN, a joint national research programme between the EU, Innovate UK, and Perspectum, began in April on 160 patients with a median age of 43.
Preliminary data found 50% of patients have evidence of either heart, liver or kidney damage.
Many patients who have had Covid, especially men, have subnormal heart pumping function. The study will look at the extent, and expected long-term impact, of Covid-19 as it continues into next year.
Is there a link between the intensity of the acute stage and Long Covid?
Researchers are finding that, certainly at this stage, there isn't.
"One thing we are learning... is we're not seeing a direct correlation between the severity of the acute illness to then who's developing these long term symptoms," Dr Evans says.
"So it's not as clear cut.
"We're seeing people where they have recovered from the intensive care unit and made a full recovery and are back to work.
“And those where they've had a relatively minor disease, acutely, but then have really developed these symptoms that just don't seem to be going away and this is after months."
Is there any treatment?
As Dr Martin Marshall, chair of the Royal College of General Practitioners and a GP at a practice in Newham acknowledges, Long Covid is “going to be a real challenge” for the health service as well as patients.
One area medicine and science is looking at is a link between Long Covid and other post-viral illnesses like ME, but at the moment, as Dr Marshall says “we're not quite sure what works, because it hasn't been around for long enough”.
He says GPs are giving patients “pretty much common sense” advice and encouraging them to boost their immune systems through healthy eating and gentle exercise.
“It feels awful when you've got the symptoms, but most people improve,” he says.
“Use your common sense in terms of resting, not overdoing it, doing a bit of exercise, but not too much - graded exercise, if you like... gentle exercise that doesn't fatigue you, doesn't wear you out is important.
“Eat well, don't drink too much.
"So standard, healthy living stuff, really, which just helps boost your immune system because it's possible that post Covid it is some kind of immune reaction or some kind of abnormal immune reaction or deficient immune reaction to the Covid itself.
"We don't know for sure, but that's one of the hypotheses.”
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How does Long Covid affect sufferers?
Matt Bromley, 40, a teacher from Altrincham in Greater Manchester, is now in week 19 of what he describes as a "rollercoaster journey".
He fell ill with presumed Covid in late March when tests for the general public were not available. But all his symptoms pointed to coronavirus and later, on his first of three visits to A&E, doctors identified that his lungs were recovering from pneumonia.
His most acute stage was during the Easter weekend, when he was unable to get up and down the stairs due to shortage of breath, a continuous cough, chest pain and chills.
Easter Sunday was "hellish" and he felt so ill he wondered whether he would live to see his son Sebastian's second birthday the following week.
But while he did survive, there has been little respite from the disease that has left him bed and garden bound, unable to look after his two young children or resume his teaching job in September.
Matt was fit and healthy with no underlying health conditions, a "natural fidget" who swam weekly, competed at a national level in dinghy sailing events and who usually spent summers exploring Scandinavia with his wife Andrea and their four and two-year-old in their camper van.
But this summer is very different.
"It's affected my life in every way and has been extremely taxing, especially with young children around the house and having been so fit and active until this started.
"After four and a half months of being unwell, it's impossible to know how long it will take me to recover," Mr Bromley said.
His current symptoms include a "horrible tightness" across his chest which he describes as feeling "like I'm being constricted around my heart by a snake".
He also has heart palpitations, headaches and dizziness.
"Talking is extremely difficult and when I do have a conversation for five minutes or so, I'll need to lie down afterwards for 45 minutes or so for it to recover," he says.
"I have also lost some dexterity in my left hand and am suffering from extreme fatigue (post viral fatigue).
"At the moment, I'm spending at least half a day in bed and the rest of it either lying down or, in better spells, sitting in a chair.
"Reading and screen time brings on an intense headache within 10 mins.
"I'm totally house and garden bound, as any physical exertion (like a five minute walk) flares up the symptoms and triggers a relapse.
"There have been a handful of encouraging days but being a novel virus, there is nobody who can say with any authority how long, or even, if I'll make a full recovery."
What help is out there now?
The NHS launched a Covid-19 rehab service last month for people who have been suffering with the long-term effects of the virus.
The Your Covid Recovery Service initially launched online but it will become a face-to-face portal when safe to do so.
When should I see my GP?
Dr Marshall said: “If patients are concerned, then that's the time to go (and see your GP) and if somebody has had Covid like symptoms, they think they've had acute Covid, and they're still getting symptoms after three weeks, I think it's perfectly reasonable after three weeks to think that now is the time to go along and see the GP.
He says that while most patients simply have to sit out the disease, visiting your GP could just help ease a worried mind that could be causing greater anxiety.
“It depends a little bit on how good you are at tolerating symptoms and tolerating that uncertainty,” Dr Marshall says.
“But I think it's perfectly reasonable if the problems are going on and you're worried about it to go along, and the GP might just reassure you if he or she is quite confident that it does look like Long Covid and can't be anything else.
“Or they might want to run a few just basic tests, like basic blood tests, to exclude anaemia or a thyroid problem.
“In conventional Long Covid, all of the tests will come back as normal.”
But in the meantime, in a world facing a disease with so many unknowns, long haulers are braced for a long road to recovery.