COVID-19 is a global emergency with over 10 million cases and over 500, 000 deaths worldwide. The SARS CoV-2 is a RNA virus belonging to the family coronaviridae. It has high infectivity. The manifestations of the disease range from asymptomatic or mild symptoms to severe pneumonia and ARDS. The CT scan of lung shows consolidation and "Ground Glass Opacities". The persons with other comorbidities are considered to be at a higher rate of acquiring the infection. Asthma and other allergies have not been identified as major risk factors for COVID-19 as the number of asthmatic patients having COVID-19 is not high enough for it to be considered so. The occurrence of COVID-19 in COPD patients can be related with smoking. The ACE-2 expression in such patients was considerably high. The relation between COVID-19 and Tuberculosis can also be reflected in terms of the stigma associated with diagnosis and treatment of such diseases in some communities, eventually increasing the chances of people's reluctance to seek medical help. Cancer patients are usually more susceptible to infections. Lung cancer is no different. Additionally, lung cancer also has strong association with smoking further increasing the risk. The risk of getting infection and its severity is high for autoimmune disorders as well as fungal infections. Currently there is no definite treatment of COVID-19. However, some of the currently used modalities are hydroxychloroquine and antiviral drugs.