Introduction: The coagulation pathway represents a balance between the procoagulant pathway. Platelets, in addition to the coagulation pathway, play a pivotal role in hemostasis and thrombosis. Any disturbance of these pathways as a result of various diseases can inhibit the protective mechanism abilities of these pathways. There are overall 10 parameters that can help in evaluating the platelet and coagulation profile of patients which helps in the diagnosis and management. Aims and Objectives: To assess and compare coagulation profile and platelet indices as a reliable early indicator of the severity of diseases like dengue, PIH, CLD, and CKD to decrease morbidity and mortality. Methods: This is a cross-sectional study done on 201 patients attending OPD and IPD of CSSH Meerut from December 2020 to June 2022, requiring laboratory and serological investigation. Results: Mean platelet count was found to be least in dengue and highest in diabetic patients and when mean platelet count was compared according to a different diagnosis, a significant difference was found with a p-value of 0.007. The coagulation parameters were also found deranged in various conditions with the values of PT and aPTT being highest in dengue and Pt values least in PIH whereas the values of aPPT were least in pyrexia of unknown origin. Conclusion: This study gives a guideline for the investigation to be done in cases of various diseases which can alert the doctor regarding the severity of the disease, so that appropriate and timely management can be initiated, which can help in reducing mortality and morbidity among patients.