The researchers systematically reviewed studies that reported post-COVID-19 complications from three databases: PubMed, Google Scholar and the World Health Organization (WHO) COVID-19 database. The search was conducted between 21 November 2020 and 14 January 2021. Inclusion criteria were articles written in English, with primary data, reporting complications of COVID-19 after full recovery. The review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) 2020 statement.

This review included 69 studies with 146 725 patients from 22 countries related to post-COVID-19 complications. Thirty-six studies reported post-cure respiratory complications, ranging from dyspnoea to residual pulmonary fibrosis. Cardiac symptoms were reported in nine studies, including palpitation, chest pain and diastolic dysfunction. Neurological complications included post-traumatic stress syndrome, anxiety, depression, memory issues, insomnia and sleeping disturbance, cognitive impairments and stigma. Gastrointestinal symptoms included nausea, vomiting, diarrhoea and acute liver injury. The physical decline was the most common symptom reported in the musculoskeletal complications.

COVID-19 may cause several types of complications after recovery (testing negative PCR). The identified complications include respiratory, neurological/mental, cardiovascular, gastrointestinal tract, urinary tract, musculoskeletal and miscellaneous complications. However, the key impairments were pulmonary consequences, psychological problems and exercise intolerance. Thus, COVID-19 patients may need long-term follow-up.