Background: Coronavirus disease-2019 (COVID-19) can cause asymptomatic, mild upper respiratory tract symptoms, pneumonia in young persons. How the disease will progress in each patient is still unknown. Therefore, we aimed to investigate the prognostic markers of the development of pneumonia and the clinical characteristics of patients under 65 years with COVID-19 confirmed by a positive reverse transcriptase polymerase chain reaction (RT-PCR) test. Method: In this retrospective study, a total of 271 patients admitted in our unit were included. The patients were divided into two groups, those who did or did not develop pneumonia. Their clinical features, treatment protocols and laboratory parameters were recorded retrospectively. Results: Pneumonia developed in 67.9% (n = 184) of the cases. Age in the pneumonia group was higher than in the non-pneumonia group (p < 0.001). In the logistic regression analysis, when symptom and comorbidity status were examined according to the presence of pneumonia; HT (OR: 4,525 95% CL: 1,494–13,708) were the most important risk factor for pneumonia. When age and laboratory values were examined according to the presence of pneumonia, advanced age (OR: 1.042 95% CL: 1.01–1.073), low albumin (OR: 0.917 95% CL: 0.854–0.986) and high troponin (OR: 1.291 95% CL: 1.044–1.596) were identified as risk factors for pneumonia. Conclusion: HT, older age, low albumin, high troponin were important factors for predicting COVID-19 pneumonia in patients under 65 years of age. Young patients with these predictive factors should be more carefully evaluated by further diagnostic procedures, such as thoracic CT. Key Words: COVID-19, pneumonia, young adults

ABSTRACT Aim: The aim of our research was to investigate retrospectively the relationship between the symptoms and general characteristics, initial laboratory values and treatments in patients who had COVID- 19 and who applied to the chest diseases outpatient clinic for control after 1 month. Methods: Three hundred fifteen patients who were diagnosed with COVID- 19 and applied to the chest diseases outpatient clinic between May 2020 and August 2020 for control in the 1st month were included in the study. Patient information was collected from the hospital information system and the e-pulse system. Results: Females accounted for 50.2 % of the our patients and their mean age was 47.98 ± 14.81 (19-88) years. 14.3% (n: 45) of the individuals were 65 years of age and older. 20.6% (n: 65) of our patients were smoking. 70.2% (n: 221) of our patients were treated at home. 133 patients had at least one comorbid disease. The patients most frequently reported cough, dyspnea, weakness, myalgia and diarrhea. The most common symptoms were cough, dyspnea, weakness and myalgia in the first month. It was determined that the symptoms had persisted in patients who had been hospitalized, had dual therapy, had comorbid diseases and had more common pathologies in their pulmonary imagings. Conclusion: Symptoms may persist for a long time in hospitalized patients, in patients with COVID-19-related pneumonia and concomitant chronic diseases and in patients with high d-dimer and high CRP at the time of admission. Patients are informed that their symptoms may last for a long time, unnecessary hospital admissons can be avoided.