While the Covid-19 pandemic has killed more than 5.6 million people worldwide, it has left millions more with continuing health problems.
In the UK alone, about 1.3 million people in private households — about 2 per cent of the population — were experiencing self-reported long Covid symptoms at the end of last year, according to the country’s Office for National Statistics (ONS).
The ONS suggests around one in seven people who test positive for Covid-19 still have symptoms 12 weeks later.
Among the array of symptoms linked to long Covid are fatigue, loss of smell, breathlessness, difficulty concentrating — often dubbed “brain fog” — headaches and muscle aches.
For those experiencing such symptoms, providers such as HCA Healthcare UK are running clinics to aid recovery.
After-effects seen at the company’s clinics are so wide that specialists including respiratory physicians, rheumatologists, gastroenterologists, radiologists, physiologists, neurologists, cardiologists, nephrologists, clinical psychologists, and rehabilitation and exercise medicine experts may become involved.
“As an initial step, patients are seen by a specialist in the area where their symptoms are most acute. They consider what tests and scans might guide treatment and they can also refer to other specialists,” the company says in a statement.
Rehabilitation programmes for the condition are likely to be around two to three years, according to Dr Raza Siddiqui, who runs the Long Covid programme at RAK Hospital, where he is executive director.
He estimates that around 5 per cent of Covid patients suffer continuing complications and says more side effects may appear.
Psychological factors play a big role, with Dr Siddiqui saying that long Covid is more common in people “who have given up, and are easily stressed or anxious”.
“Long Covid is a combination of factors,” he said.
“We only have data for 18 months or so, but depression is a common theme among our patients, and this attracts other complications. Patients must have a strong desire to recover.”
Indeed, studies have shown that a person’s state of mind before they are infected affects their likelihood of developing long Covid, says Prof Paul Hunter, a professor in medicine and an infectious diseases specialist at the University of East Anglia in the UK. Post-viral syndromes generally are “very difficult topics to address”.
“It’s real, but how common it is is still difficult to know for certain,” he says.
“Most studies that have addressed this are known to be highly prone to bias.
“They say, ‘Are you experiencing symptoms?’ We all experience symptoms all the time. If you’ve had Covid, you may be experiencing symptoms because … you’ve got long Covid or think you have. Higher quality studies have come up with lower estimates.”
Comparisons with other post-viral syndromes suggest that most people will eventually get over their symptoms, he said.
'Some people may never return to normal'
While most people are likely to improve over time, Dr Andrew Freedman, an infectious diseases specialist at Cardiff University in the UK, says some people may never return to normal.
“Those who had severe organ damage — lungs or other organs — may not recover completely,” he says.
Vaccination is thought by doctors to reduce a person’s chance of developing long Covid. Therefore, as more of the world’s population is jabbed, the numbers of patients with the condition is likely to fall.
It may also become rarer if Covid-19 transitions to being an endemic disease associated with less severe illness.
“Other coronaviruses cause common colds — they don’t usually leave lasting symptoms after the infection, so probably Covid will be much the same,” Dr Freedman says.
For the moment, though, people with long covid require help to recover.
At London’s Cromwell Hospital, which is run by a private healthcare provider BUPA, initial assessment in the Long Covid Clinic often involves blood tests, detailed evaluation of heart and lung function and, where necessary, tests on the neurological, hormone and musculoskeletal systems.
“The most common demographic we’re seeing in our clinic is women aged between mid-20s and mid-50s,” says Dr Brian O’Connor, a consultant in respiratory medicine and lead consultant at the Long Covid Clinic.
“These women tend to be high achieving and often have children. The reason they perhaps suffer most with long Covid could be due to the fact they’re returning to a full-on lifestyle too quickly and not allowing their bodies to recover.”
Most patients at the clinic have typically had mild Covid-19, but their rapid return to full-time work or a high-intensity exercise regime may have caused symptoms to persist.
An exercise regime that is built up gradually can aid recovery, as can a daily routine in which tasks are completed in the morning, when energy levels are higher. Dr O’Connor says people should go at their own pace and not take on too much as they recover. Experience shows, he says, that symptoms typically do improve over time.
“We’re still seeing patients come forward to access the long Covid Clinic at the Cromwell Hospital, as often there’s a lag between having Covid and patients feeling that they are still not fully recovered,” he says.
“I anticipate that rates of long Covid will decrease as more people are fully vaccinated, as fewer people develop Covid in the first place.”