The main symptoms of coronavirus are listed by the NHS as a high temperature, a new, continuous cough and a loss or change to your sense of smell or taste. But as scientists have learnt more about the virus, other symptoms have been noted, such as diarrhoea, conjunctivitis and a rash on skin.
In the new study, researchers found more than 80 percent of hospitalised coronavirus patients experience headaches, dizziness, muscle pain and encephalopathy, also known as altered mental function.
The average hospital stay for patients with these symptoms was also found to be three times longer, with the risk of death seven times higher.
The researchers, from Northwestern Memorial Hospital in Chicago, said the study is the first of its kind in the US and could help identify and treat people hospitalised with the virus before they experience these symptoms.
As part of the study, published in the Annals of Clinical and Translational Neurology, the team looked at data of more than 500 patients with COVID-19 at 10 hospitals in the Northwestern Medicine health system.
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It was revealed 42 percent had neurological symptoms when their symptoms began, and 63 percent suffered them while in hospital.
But a huge 82 percent experienced at least one symptom during the course of their illness.
Around 45 percent of patients suffered muscle pain, and around 38 percent reported headaches.
Approximately one-third experienced dizziness and encephalopathy, around 16 percent had taste disorders and 11 percent reported smell disorders.DON'T MISSFull list of 172 ‘long COVID' coronavirus symptoms - from belching to bedwetting [INSIGHT]The two surprising first symptoms of COVID explained - and it's not the ‘classic' three [STUDY]The most common coronavirus symptom in frail over 65s - it is not one of the ‘main three' [EXCLUSIVE]
Less than two percent of patients experienced severe complications, such as seizures, strokes and movement disorders.
After the patients were discharged from hospital, more than two-thirds with encephalopathy were unable to care for themselves at home.
The nearly 90 patients who didn't develop this condition were able to take care of themselves after leaving hospital.
The death rate was found to be higher among encephalopathy patients.
Dr Igor Koralnik, chief of neuro-infectious diseases and global neurology at Northwestern Medicine, said: "We are now looking to characterize the long-term neurologic effects of COVID-19 and the cognitive outcomes in patients with COVID-19-associated encephalopathy.
"We're studying this in patients who are discharged from the hospital, as well as in COVID-19 'long-haulers,' who have never been hospitalised but also suffer from a similar range of neurological problems, including brain fog."
The UK government's advice on coronavirus symptoms still remains the same.
It says if you experience any of the main symptoms of coronavirus - a high temperature, a new, continuous cough, and a loss or change to your sense of smell or taste, you should get a test to check if you have the virus as soon as possible.
You should then stay at home and not have visitors until you get your test result - only leave your home to have a test.
If you're worried about your symptoms or you're not sure what to do, use the NHS 111 online coronavirus service.
If you cannot get help online you can call 111.
But avoid going to places like a GP surgery, hospital or pharmacy.