The current COVID-19 pandemic is caused by the novel SARS-CoV-2 coronavirus strain. Although SARS-CoV-2 infection can affect everyone, the kind and degree of infection and sickness vary widely between individuals and populations. It has been crucial since reported disease loads and case fatality rates vary greatly among countries. However, there are still uncertainties about the severity of the illness in certain people and, in other cases, the aetiology of a more severe illness. Various chronic conditions, such as diabetes, cardiovascular diseases, respiratory ailments, and immunodeficiency disorders, have been identified as significant risk factors for COVID-19. These comorbidities not only increase the susceptibility to contracting the virus but also exacerbate the severity of symptoms and the likelihood of adverse outcomes, including hospitalization, intensive care unit admission, and mortality. The objective of this article is to point out the proliferation of COVID-19 in relation to different diseases affecting the clinical outcome of COVID-19. The study included 1500 patients with various diseases such as HCV, HBV, kidney disease, heart disease, asthma, T.B., arthritis, smokers, and vaccinated or unvaccinated. Results showed that 22% of diabetic patients, 40% of heart patients, 40% of asthma patients, 26% of kidney patients, 25% of T.B patients, and 41% of smokers had high corona positive. Coronavirus positivity was found in 34% of vaccinated patients and 72% of non-vaccinated patients, with an overall calculated p-value of 0.0001 by ANOVA statistical analysis. The overall outcome of the results showed that the severity of Corona disease increased in relation to different diseases.