'Long COVID' Can Last up to 2 Years

Aftereffects of COVID-19 such as fatigue and breathing problems can persist for up to two years after recovery from the initial infections, domestic studies confirm.

Health authorities on Thursday said studies about long-term COVID effects by the Korea National Institute of Health found that fatigue, breathing problems, "brain fog" like forgetfulness, sleep and mood problems can persist among 20 to 79 percent of former patients for more than three months.

In a study of 81 patients who were infected with COVID in February and March 2020, Kyungpook National University Hospital found that memory problems, fatigue, and sleep problems persisted among more than two-thirds for up to 21 months, while three-quarters suffered from lasting effects for more than a year. 

In another study of 47 patients from January 2020 to June 2021, the National Medical Center also found that fatigue and difficulty breathing during exercise persisted among some of them for 19 months. About half of them complained of fatigue in the 12 month after infection and one-third in the 19th month. Also people continued to have breathing problems or feel chest pains until 19 months later, although they slowly got better. 

In a more comprehensive study of 21,615 patients who were treated for COVID between January and September 2020 based on data from the Health Insurance Review and Assessment Service, 19.1 percent visited hospitals because of lingering effects after recovery. Compared to flu patients, they were more likely to suffer from mood problems, dementia, heart failure or hair loss.

Based on a study of patients from April to October in 2021, Yonsei University's Severance Hospital concluded that some 20 percent continued to suffer aftereffects until three months after infection.

Overseas studies also suggest that 30 to 40 percent of COVID patients suffer from lingering effects.