Patients presenting with altered mental health and behavior may be misdiagnosed with psychiatric disorders when organic causes are at play. This article discusses two case studies illustrating the psychiatric manifestations associated with acute medical illnesses, emphasizing the importance of thorough assessment before concluding a psychiatric diagnosis. The first case involves a young woman who developed acute psychotic symptoms following a recurrent ear infection, which resolved completely after antibiotic treatment, with no lasting effects. In contrast, the second case presents a woman with psychosis following confirmed herpes simplex viral encephalitis, leading to significant brain injury and ongoing psychiatric symptoms. These cases highlight the need for timely identification and management of medical conditions presenting with psychiatric symptoms to prevent long-term complications. The interplay of infections and mental health is further explored, emphasizing the necessity of integrating medical and psychiatric care.