Toxic/metabolic | Drugs | Antibiotics | Antiseizure medications | Cytotoxic chemotherapy | Digitalis | Iron | NSAIDs, aspirin | Opioids, tramadol | SSRIs and bupropion | Theophylline | Many other drugs | Organ failure | Liver, renal | Metabolic | Hypercalcemia | Hyponatremia | Ketoacidosis | Poisoning, substance abuse | | Disorders of viscera | Obstruction | Biliary/pancreatic duct | Gastric outlet | Small bowel | Hepatomegaly | Severe constipation | Gastroparesis | Inflammation/irritation | Chemotherapy (direct gastrointestinal effects) | Cholecystitis | Gastritis | Gastroenteritis | Hepatitis | NSAID | Pancreatitis | Radiation | Tumors of the gastrointestinal tract and thorax | Ascites | | CNS causes | Increased intracranial pressure | Abscess | Cranial irradiation | Hemorrhage | Malignancy | Meningeal infiltration | Vestibular | Drug effects | Labyrinthitis | Anxiety | Anticipatory nausea and vomiting | Pain | |