Still struggling with symptoms beyond what is considered to be the normal duration of Covid-19 people took to the internet during lockdown, and discovered that they were not alone. Part internet phenomenon and mostly unknown - researchers, governments, and organisations are beginning to understand and treat long Covid.

This week the National Institute for Health Research (NIHR) released a review on the evidence surrounding experiences of long Covid. This review examined both the available academic research about the subject and gathered the personal experiences of a members of a long Covid Facebook group.

The various and fluctuating symptoms of long Covid

Due to various reported symptoms, of the fittingly variously named long Covid/post-acute-Covid-19/ongoing Covid-19, it has been defined as a multisystem disease that is experienced for weeks or months after the initial Covid-19 infection.

While currently the causes of long Covid are speculative, symptoms tracked by nature medicine include:

  • Loss of smell.
  • Loss of appetite.
  • Cognitive problems.
  • Fever.
  • Persistent cough, hoarse voice, and shortness of breath.
  • Delirium.
  • Chest and abdominal pain.

With one responder to the NIHR survey replying that: “At the time I didn’t really notice I was unwell but over the following few weeks I noticed that I seemed to be unable to recover and I was now suffering with a crippling fatigue as well as the other symptoms of exhaustion, a strange taste, and brain fog.”

Symptoms of long Covid have been experienced post-illness by 10% according to the Zoe Covid Symptom Study, and up to 87% for one symptoms and a further 55% with three or more symptoms for two months afterwards according to an Italian study.

It is worth noting that previous coronavirus epidemics - such as SARS and MERS – have also had enduring health consequences, which the NIHR report highlighted by referencing studies that indicate that survivors experienced long term lung damage, physiological and psychological impairments, and heart complications.

Additionally a similar comparative study again in terms of SARS and MERS, published in The Lancet Psychiatry, concluded that that depression, anxiety, fatigue, and PTSD were long term post-illness features of those two epidemics.

Similarly because of their vulnerability to Covid-19 and likelihood of suffering from more acute symptoms, geriatric medical research has shown that older patients are high risks post-illness for sarcopenia, malnutrition, depression, and delirium.

And another study demonstrated that post-Covid-19 chronic pain (pain that lasts more than 12 weeks) is also more commonly experienced by older ICU patients.

The diagnostic ambiguity of long Covid and four potential causes

Persistent symptoms of long Covid according to the NIHR review can be categorised and localised to the respiratory system, the heart and cardiovascular system, the brain both directly and indirectly, the kidneys, and the gut. Although the definitive causes of these symptoms are mostly unknown, with the term long Covid standing in for possibly various separate psychological and physiological conditions.

Due the diagnostic uncertainty surrounding the sources of the symptoms that make up long Covid, the NHIR review hypothesised that long Covid symptoms may fit into the four categories of:

  • Permanent organ damage to the lungs and heart;
  • Post-intensive care syndrome;
  • Post-viral fatigue syndrome;
  • And continuing Covid-19 symptoms.

Post-viral fatigue syndrome (PVFS), which is often conflated with chronic fatigue syndrome as they share similarities, is triggered after an acute viral infection. Although also comparable with long Covid  as experts are unsure as to the cause of PVFS symptoms - which include cognitive problems, sore throat, swollen lymph nodes, and muscle pain.

Interestingly the source and the signs of long Covid are comparable to PVFS as well - with one theory to the cause of PVFS being that there is an overreaction of the immune system, that causes a cytokine storm. Cytokines are proteins that coordinate the body’s immune response to infection, but during a cytokine storm the body over produces these cytokines creating uncontrolled hyperinflammation – which has been linked to Covid-19.

Although some argue that symptoms of chronic fatigue syndrome, PVFS, and long Covid are psychosomatic and are a consequence of mental trauma resulting from an acute illness – with the physical symptoms arising from the traumatic mental state.

Treating long Covid

Going forward the recommendations of the NIHR review based on the experiences of long Covid suffers included improved signposting to the appropriate services – as many people responded that they struggled to access the correct services because of the changing and multiple symptoms of the disease and the healthcare services atomised structure.

As well as improving access to rehabilitation serves, as the report reflected that these services should be more openly available for those who did not need to go into hospital during their illness, which they said suggests that an aftercare plan needs to be formalised specifically for Covid-19.

These recommendations built on other recent announcements addressing this medical phenomenon, with NICE and SIGN saying that due to the diagnostic ambiguity of long Covid they were developing together a criterion for the illness. And also, last week new plans were announced by NHS England chief executive Sir Simon Stevens, who committed £10m in funds for the setting up of regional specialist long Covid clinics.