Hyperthyroidism

A patient with new atrial fibrillation, tremor, heat intolerance, or unexplained weight loss may have excess thyroid hormone, but the laboratory picture does not by itself identify the cause. Graves disease and autonomous nodules actively synthesize hormone; thyroiditis releases hormone already stored in the gland. That mechanistic distinction predicts whether an antithyroid drug can help. NP reasoning therefore follows a sequence: confirm biochemical thyrotoxicosis, identify its source, look for cardiac or systemic decompensation, and then match symptom control and definitive or cause-directed therapy to the patient. Pregnancy, breastfeeding, eye disease, osteoporosis, atrial fibrillation, heart failure, medication interactions, and patient preference can change the safest option. The endpoint is not merely a lower T4; it is controlled adrenergic stress, restored euthyroidism, and timely escalation when the patient may be entering thyroid storm.