Some causes are related the cancer, some to the cancer therapy, some to complications and some to unrelated conditions.
Causes for hiccups include:
(1) location and type of cancer (see below)
(2) electrolyte disorder (hyponatremia, hypokalemia, hypocalcemia)
(3) endocrine disorder (uncontrolled diabetes mellitus, hypoadrenalism)
(4) brain disorder other than tumor (stroke, hemorrhage, encephalitis, meningitis, abscess)
(5) cardiac disorder (myocardial infarction, pericarditis, pericardial effusion)
(6) pulmonary disorder (pneumonia, pleural effusion, mechanical ventilation)
(7) gastrointestinal and abdominal disorder (see below)
(8) surgery and/or general anesthesia
(9) psychogenic
(10) epidural injections with a local anesthetic agent
(11) drug-related, including chemotherapy
(12) infection (subdiaphragmatic abscess, thoracic herpes zoster, organ specific)
(13) renal failure
Tumors associated with hiccups include:
(1) esophageal cancer
(2) gastric cancer
(3) lung cancer
(4) colon cancer
(5) hepatoma or liver metastases
(6) pancreatic cancer
(7) renal cancer
(8) leukemia
(9) malignant lymphoma
(10) brain tumor
Gastrointestinal and abdominal disorders include:
(1) esophagitis (reflux, infective)
(2) peptic ulcer disease
(3) gastric distention including gastric outlet obstruction
(4) small bowel obstruction
(5) pancreatitis
(6) cholecystitis
(7) ascites
