INTRODUCTION:
The Centers for Disease Control and Prevention (CDC) defined long COVID as new, recurring, or ongoing health problems that people may experience four or more weeks after being infected with the virus that causes COVID-19, and noted that prevalence estimates for long COVID range from 10 to 35% or more. The aim of the study was to analyze the symptoms and main risk factors for long COVID.

METHODS:
Case-control study comparing the proportion of individuals with clinical characteristics in cases and controls who presented with COVID-19 in health units in Brazil. Cases were subjects with long COVID-19 (Individuals who presented with persistent symptoms lasting more than 90 days after the acute phase) and controls without prolonged symptoms. Crude and adjusted odds ratios (OR) and their respective 95% confidence intervals (95% CI) were estimated using binary logistic regression.

RESULTS:
In the multivariate analysis, the clinical characteristics associated with a higher chance of long-term COVID were hypertension (OR=2.44; 95% CI: 1.54 - 3.85); dyspnea (OR=2.52; 95% CI: 1.52 - 4.19); constipation; stomach pain (OR=2.63; 95% CI: 1.31 - 5.27), nausea (OR=2.07; 95% CI: 1.11 - 3.85) and loss of appetite (OR=3.20; 95% CI: 1.91 - 5.37); persistent headache (OR= 2.03; 95% CI: 1.23 - 3.31), memory loss (OR=6.59; 95% CI: 3.76 -11.50), vision problems (OR= 2.17; 95% CI: 1.05 -4.48) and dizziness (OR=2.52; 95% CI: 1.18 - 3.55); difficulty concentrating (OR= 1.99; 95% CI: 1.13 - 3.49) and excessive sleepiness (OR= 2.52; 95% CI: 1.08 - 5.89).

CONCLUSIONS:
The findings contribute to the understanding of the long-term effects of COVID-19 manifestations and their impact on the quality of life of recovering patients, and have the potential to assist the health system by indicating which services should improved to care for the population affected by long COVID syndrome.