A dangerous symptom of the coronavirus that can cause a patient to fall unconscious or even die is known as hypoxia — when the body’s tissues do not receive enough oxygen.
Shortness of breath often accompanies hypoxia as an indicator that the body’s oxygen levels have dropped, said Dr. Ron Damant, a professor at the University of Alberta who specializes in pulmonary medicine.
This can lead to death if it’s severe enough, he said. But a phenomenon called “silent hypoxia”, when oxygen levels fall but an individual feels no symptoms or signs that something is wrong, is an effect of the coronavirus that some doctors are seeing in patients.