When is it considered to have prolonged Covid-19 syndrome?

Long-lasting Covid syndrome or post-Covid-19 is abnormal health symptoms with no known cause, occurring after 4-12 weeks of recovery, as defined by WHO. Mr. Loc, 62, in Ho Chi Minh City, contracted Covid-19 in January, symptoms of cough with sputum, shortness of breath, chest pain, SpO2 (capillary blood oxygen concentration) measurement sometimes decreased to 92%. […]