Electrolyte Imbalances Electrolyte imbalances such as hypokalaemia, hyponatraemia and hypercalcaemia suggest the presence of ectopic ACTH, ADH and PTHrP syndromes, respectively, and metabolic abnormalities such as diabetes mellitus are associated with the ectopic ACTH syndrome. These electrolyte and metabolic imbalances are frequently encountered as the only detectable signs of ectopic humoral syndromes. See also: • Ectopic Antidiuretic Hormone Syndrome • Ectopic Adrenocorticotrophic Syndrome • Hypercalcaemia of Malignancy