In criminal investigations, forensic bodily fluid analysis is essential since it provides evidence for identifying suspects, reconstructing crimes, and other legal situations. However, a person’s disease states can have a significant impact on bodily fluids’ physical, chemical, and biological characteristics, which could change the results of forensic tests. Diabetes, infections, metabolic diseases, and chronic illnesses are examples of pathological situations that alter the quantities of biomarkers, proteins, DNA, and metabolites, which in turn affect the composition of fluids such as blood, saliva, semen, and urine. These modifications may put traditional forensic techniques to the test, which could result in less reliable results and possibly incorrect evidence interpretation. Accurate DNA profiling may be hampered, for instance, by high blood glucose levels in diabetics or damaged DNA from infections. Similar to this, changes in salivary proteins brought on by oral infections or decreased seminal volume as a result of reproductive diseases might make it more difficult to identify bodily fluids in forensic investigations. Analyte concentrations in fluids are also impacted by illnesses such as liver and renal disease, which might have an impact on toxicological and biochemical tests. By highlighting particular difficulties and their consequences for legal decisions, this study summarizes previous studies to investigate how disease states affect the forensic investigation of bodily fluids. It also looks at new developments in forensic methods that promise to address these issues, like metabolomics and nextgeneration sequencing. The integrity of evidentiary procedures can be preserved and analytical accuracy increased by forensic science through the comprehension and management of disease-related variability. In order to adapt forensic procedures to the complications imposed by disease states, this research emphasizes the necessity of interdisciplinary collaboration and creative approaches.