There may be more than 200 symptoms of long Covid, according to a global study.
Little is known about the debilitating condition, which can see survivors left battling fatigue and headaches months after beating the virus.
But researchers are now getting closer to understanding the vast range of symptoms linked with the condition and how long they last.
They say each long Covid patient suffers an average 56 different symptoms over the course of their recovery – including bizarre ailments such as noting their penis shrink in size and irregular period.
University College London experts quizzed almost 4,000 ‘long haulers’ from around the world about their post-Covid experience.
Patients reported a mix of 203 symptoms, with participants experiencing an average of 56 different ones, on average.
Researchers found the symptoms affect 10 different organs, including the heart, lungs, brain and bowel.
The researchers found that the probability of still suffering from symptoms after becoming infected decreased over time (left). The prevalence of very mild and mild symptoms increased over time, while moderate symptoms plateaued after six months. But severe and very severe symptoms became less common over time (middle). People who recovered in 90 days of catching Covid found that their symptoms progressively improved, but for those who still had problems after 90 days found that their symptoms stopped improving after six months (right)
Fatigue was the most common symptom, affecting an estimated 535,000 people, followed by shortness of breath striking 397,000 and muscle ache hitting 309,000, according to the Office for National Statistics
Tiredness was the most common symptom, with 98.3 per cent of the over-18s who were asked suffering from it.
This was followed by post-exertional malaise (89 per cent), which is the worsening of symptoms after physical or mental exercise, and brain fog (85.1 per cent).
Others reported hallucinations, tremors, itchy skin, changes to the menstrual cycle, sexual dysfunction, heart palpitations, diarrhoea and tinnitus.
Not all of the reported symptoms are definitely going to be caused by long-Covid, as the study was merely based on responses from affected patients — it means over-reporting is possible.
Experts found 96 per cent of volunteers had symptoms for three months, while 91.8 per cent were still suffering after eight months.
People who recovered quicker had few symptoms — reaching a maximum of 11 at once — but people who had the condition for more than seven months went on to experience up to 17 symptoms at once.
The report — which was published today in the Lancet’s EClinicalMedicine journal — is the largest international study of long Covid patients.
The research team, that worked with UCL scientists, all have long-Covid and want clinical guidelines for assessing the condition to be widened because lots of patients ‘suffer in silence’.
The NHS lists 21 different symptoms for the condition, including tiredness, shortness of breath and chest pain.
Studies estimates that up to 30 per cent of people who have symptomatic Covid will still be suffering 12 weeks later.
Doctors can diagnose long-Covid by asking patients about their symptoms. There is currently no cure for the condition, so patients are given advice on how to self-manage their symptoms.
Dr Athena Akrami, senior author of the study, said: ‘While there has been a lot of public discussion around long Covid, there are few systematic studies investigating this population.
‘Hence relatively little is known about its range of symptoms, and their progression over time, the severity, and expected clinical course (longevity), its impact on daily functioning, and expected return to baseline health.
‘In this unique approach, we have gone directly to long haulers around the world in order to establish a foundation of evidence for medical investigation, improvement of care, and advocacy for the long Covid population.
‘This is the most comprehensive characterisation of long Covid symptoms, so far.’
NHS England has already created 89 clinics to offer specialist care and worked with the National Institue of Health Research to give £50million to fund research of the condition.
Meanwhile, the National Institute for Health and Care Excellence has published guidance for doctors on how to manage the condition.