<prompt> Syndrome of inappropriate antidiuretic hormone secretion SIADH causesEuvolemic hyponatremiaHypovolemic hyponatremiaHypervolemic hyponatremiaHypernatremia  <response>: 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 