This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fluid and electrolytes, Subject name: Medicine
[{'content': 'Syndrome of inappropriate antidiuretic hormone secretion (SIADH) causes \nSelect and explain. \nA. Euvolemic hyponatremia, B. Hypovolemic hyponatremia, C. Hypervolemic hyponatremia, D. Hypernatremia', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The syndrome of inappropriate antidiuresis (SIAD) is the most frequent cause of euvolemic hyponatremia. Glucocoicoid deficiency, Hypothyroidism, Stress, Drugs are other causes of euvolemic hyponatremia. Common causes of SIAD include pulmonary disease (e.g., pneumonia, tuberculosis, pleural effusion) and central nervous system (CNS) diseases (e.g., tumour, subarachnoid haemorrhage, meningitis). SIAD also occurs with malignancies, most commonly with small-cell lung carcinoma (75% of malignancy-associated SIAD) SIAD is also a frequent complication of ceain drugs, most commonly the selective serotonin reuptake inhibitors (SSRIs). Ref: Harrison 19e pg: 300', 'role': 'assistant'}]