Doctors are warning of a hidden symptom of the new coronavirus which they are struggling to explain - and which could be extremely dangerous.
Medics say they are unable to explain how people are presenting with the condition, which should leave them unconscious.
The condition - called Happy Hypoxia - means patients have extremely low oxygen levels in their blood, but are not showing the usual symptoms.
Low levels of oxygen should leave patients in distress or unconscious, making the condition much clearer for doctors.
Low oxygen levels can damage organs and quickly prove fatal.
Speaking to The Guardian, Dr Jonathan Bannard-Smith, a consultant in critical care at Manchester Royal Infirmary, said: “It’s intriguing to see so many people coming in, quite how hypoxic they are.
“We’re seeing oxygen saturations that are very low and they’re unaware of that. We wouldn’t usually see this phenomenon in influenza or community-acquired pneumonia.
“It’s very much more profound and an example of very abnormal physiology going on before our eyes.”
Dr Mike Charlesworth, an anaesthetist at Wythenshawe Hospital, said: “With pneumonia or a pulmonary embolism they wouldn’t be sat up in bed talking to you. We just don’t understand it.
“We don’t know if it’s causing organ damage that we’re not able to detect. We don’t understand if the body’s compensating.”
Scientists suggest that subtle clotting in the lungs could set off a cascade of proteins that prevent the blood from getting enough oxygen.
Based on the findings, scientists are urging doctors to avoid aggressive treatments including ventilators unless completely necessary.
For example, a study last month found that flipping patients onto their stomachs could improve their oxygen levels, without the need for a ventilator.
