Endocrine & reproductive — DM, thyroid, HPA axis
**Diabetes (ADA 2024):** Dx — A1c ≥6.5%, FPG ≥126, 2-hr OGTT ≥200, random ≥200 with symptoms. • **T1DM** — autoimmune β-cell destruction, C-peptide low, antibodies (GAD, IA-2, insulin). DKA risk. • **T2DM** — insulin resistance + relative deficiency. First-line metformin; add GLP-1 RA or SGLT2i for ASCVD/HF/CKD (ADA 2024 priorities over sulfonylureas). • **DKA** — insulin drip, fluids, replace K+ (hypokalemia with insulin). • **HHS** — T2DM, glucose >600, osm >320, minimal ketones.
**Thyroid:** • Hyper — Graves (TSI), toxic MNG, silent/postpartum, iodine-induced. Tx: methimazole (teratogen 1st trim — PTU instead), RAI, surgery. • Hypo — Hashimoto (anti-TPO), iodine deficiency, postablation. Levothyroxine. Myxedema coma: IV levo + glucocorticoid.
**Adrenal (HPA axis):** • **Cushing** — ACTH-dependent (pituitary = Cushing disease; ectopic small-cell), ACTH-independent (adrenal adenoma, iatrogenic steroids — most common). Dx: 24-hr UFC, late-night salivary cortisol, low-dose dex suppression. • **Addison** — primary adrenal insufficiency. Hyperpigmentation, hyponatremia + hyperkalemia, low aldosterone. ACTH stim test. • **Pheochromocytoma** — 5-H's; plasma metanephrines. Block α (phenoxybenzamine) BEFORE β. • **Hyperaldosteronism (Conn)** — HTN + hypokalemia. Aldo/renin ratio.
**Reproductive physiology:** HPG axis — GnRH → LH/FSH → gonadal steroids. Menstrual cycle: follicular → ovulation (LH surge) → luteal (progesterone). PCOS: Rotterdam — oligo/anovulation + hyperandrogenism + polycystic ovaries (2 of 3).