Topic overview

Start with the big picture

Diabetes mellitus involves persistent hyperglycemia arising from absolute insulin deficiency or relative deficiency and resistance. Its presentation may include polyuria, polydipsia, and polyphagia; acute complications include diabetic ketoacidosis and hyperosmolar hyperglycemic state, while long-term effects involve microvascular and macrovascular disease. Hypothyroidism is associated with reduced thyroid hormones and, in primary disease, elevated TSH; features include fatigue, weight gain, cold intolerance, and slowed reflex relaxation. Addison’s disease is primary adrenal insufficiency, typically involving reduced cortisol and aldosterone with increased ACTH. Hyperpigmentation, orthostatic hypotension, electrolyte changes, and salt craving are distinguishing clues. The lesson also addresses severe presentations, diagnostic testing, and treatment principles for each disorder.