Abstract
The syndrome of inappropriate antidiuretic hormone secretion is a condition marked by the excessive production of antidiuretic hormone, potentially resulting in hyponatremia. If not properly managed, severe hyponatremia can result in seizures, cerebral edema, and even death. There are many causes of this inappropriate release of antidiuretic hormone, including malignant tumors, central nervous system infections, drug-induced factors, and hypothalamic-pituitary-renal axis disorders. Current evidence suggests that viral encephalitis-related SIADH manifestations are markedly underrepresented in existing medical reports. We reported a case of elderly SIADH with persistent dizziness and fatigue as the main symptoms. Through multidisciplinary comprehensive analysis and discussion, and after excluding various factors, we considered it to be caused by viral encephalitis, which is rare in clinical practice. The SIADH is a clinically challenging disease that can severely impact a patient's health and quality of life. General practitioners need to consider multiple factors when diagnosing and treating this condition, leveraging their expertise, collaborating with multidisciplinary teams, and focusing on early identification and accurate diagnosis. They should develop individualized treatment plans and implement comprehensive management strategies to ultimately cure the patient.