High risk individuals in COVID-19 pandemic; an updated review

In December 2019, cases of pneumonia with an unknown pathogen were reporting in Wuhan city, China. The World Health Organization (WHO) recognized it as a pandemic, on March 11, 2020. The most frequent site of involvement is the respiratory system. The most common symptoms include cough, fatigue and fever. In some cases, neurological, respiratory and gastrointestinal complications can lead to death. Inflammatory cytokines can play a major role in pathogen damage. Due to the pandemic of COVID-19 and its severe complications, it is critical to identify the high-risk groups. Since this disease has a rapid transmission, following the instructions announced by the WHO, prevention is vital, especially in people with risk factors for disease complications and mortality. According to the latest reports by CDC (Center for Disease Control and Prevention), older age and having some medical conditions such as smoking, obesity (BMI >= 30 kg/m(2)), chronic obstructive pulmonary disease (COPD), heart disease, cancer, solid organ transplant, type 2 diabetes mellitus, chronic renal failure, and sickle cell anemia in younger adults are known disease severity risk factor.