Self-limited disease often following a flu-like illness (eg, viral infection).

May be hyperthyroid early in course, followed by hypothyroidism (permanent in ~15% of cases).- Do not have increased radioactive iodine uptake, "leaks" thyroid hormone out of damaged gland.

Histology: granulomatous inflammation with multinucleated giant cells, disrupted follicles

Findings: ↑ ESR, jaw pain, very tender thyroid.