• Hyponatremia

Central nervous system disorders

• Head trauma
• Stroke
• Subarachnoid hemorrhage
• Hydrocephalus
• Brain tumor
• Encephalitis
• Guillain-Barré syndrome
• Meningitis
• Acute psychosis
• Acute intermittent porphyria

Pulmonary lesions

• Tuberculosis
• Bacterial pneumonia
• Aspergillosis
• Bronchiectasis
• Neoplasms
• Positive pressure ventilation

Malignancy

• Bronchogenic carcinoma
• Pancreatic carcinoma
• Prostatic carcinoma
• Renal cell carcinoma
• Adenocarcinoma of colon
• Thymoma
• Osteosarcoma
• Malignant lymphoma
• Leukemia

Drugs

• Increased ADH production

1. Antidepressants: tricyclics, monoamine oxidase inhibitors, SSRIs
2. Antineoplastics: cyclophosphamide, vincristine
3. Carbamazepine
4. Methylenedioxy-methamphetamine (MDMA; Ecstasy)
5. Clofibrate
6. Neuroleptics: thiothixene, thioridazine, fluphenazine, haloperidol, trifluoperazine

• Potentiated ADH action

1. Carbamazepine
2. Chlorpropamide, tolbutamide
3. Cyclophosphamide
4. NSAIDs
5. Somatostatin and analogues

Others

• Postoperative
• Pain
• Stress
• AIDS
• Pregnancy (physiologic)
• Hypokalemia