Hyperthyroidism: 1.3% of the US population has hyperthyroid. Thyrotoxicosis = too much thyroid hormone activity. Remember, T4 is a prohormone and T3 is the bioactive form. Causes of hyperthyroidism are broad and include: inappropriate thyroid stimulation, autonomous release of excess thyroid hormone, excessive release of thyroid stores, extra-thyroid sources of hormone. Hyperthyroidism increases risk of all-cause cardiovascular mortality and incidence of Afib. Diagnosis of hyperthyroid made by TSH <0.1 and high free T4. Iodine uptake test helps to find nodules and differentiate from thyroiditis. 

Thyroid Storm: an exacerbation of thyrotoxicosis leading to multi-organ failure. Mortality is high at 10-30%. Precipitating factors include: thyroid surgery, radioiodine treatment, medication and medication adjustment. Symptoms: febrile, tachycardic, agitation, seizures, psychosis, delirium, transaminitis. Diagnostic scoring system based upon signs and symptoms, not lab values. Treatment: propylthiouricil is available but not commonly recommended due to hepatic toxicity. Methimazole is preferred, but takes several hours to work. In the mean-time, use propanolol to decrease the effects of the hormone (the only beta blocker that crosses the BBB so is ideal at treating CNS symptoms). 1 hour after giving methimazole, can give iodine.