 Welcome to emergency medicine video series. This video will focus on thyroid storm. In part 1 we will discuss the causes and symptoms of thyroid storm. In part 2 we will discuss the diagnosis and treatment in the emergency department. What is thyroid storm? Thyroid storm is a form of hyperthyroidism where there is too much thyroid hormone. It sits at the extreme end of hyperthyroidism. It is defined as hyperthyroidism with end organ dysfunction, particularly with cardiac and neurological effects. Patients with thyroid storm therefore have exaggerated clinical features of hyperthyroidism. What are those clinical features? Well they mainly affect three different parts of the body. The heart, the brain and the GI tract. In the heart in simple hyperthyroidism there is tachycardia and palpitation. As the patient gets into thyroid storm the symptoms become much worse. Now there are tachy arrhythmias, chest pain and palminar edema leading to shortness of breath. In the brain in hyperthyroidism patient might feel nervous and jittery. In patient with thyroid storm the patient now becomes agitated and psychotic. They may even have seizures. Sometimes the patient could also be fibrous as well. In the GI tract in hyperthyroidism there is weight loss from vomiting and diarrhea. In thyroid storm more vomiting and diarrhea might lead to hypotension and shock. In short the thyroid storm patient might present with fever and in the heart tachycardia arrhythmia, CHF, shock. And in the CNS agitation, confusion, coma or seizures. These are sick patients and thyroid storm is a medical emergency. We have to pick out these patients early and treat them aggressively. What are the causes of thyroid storm? Thyroid storm usually needs a pre-existing hyperthyroid state plus a trigger. First let's look at hyperthyroid state. If we look at the hypothalamus, pituitary gland, thyroid gland axis. The hypothalamus secretes thyroid releasing hormone into the pituitary gland causing it to release thyroid stimulating hormone. That thyroid stimulating hormone causes thyroid gland to secrete T3 and T4. Those are a thyroid hormone. Let's say if there's something wrong with the pituitary gland that there is a pituitary adenoma that causes more TSH production that in turn will causes more T3 and T4. Most hyperthyroidism problem however lies in the thyroid glands itself. Let's look at them. First, Graves disease. This is an autoimmune disease of the thyroid causing more thyroid hormone to be released. Patients might have exothermos in addition to the other hyperthyroid symptoms that we discussed. Another problem of the thyroid could be a multinodular goiter as evident here. Hyperthyroid state can also be caused by thyroiditis such as decoranes, thyroiditis or postpartum thyroiditis. These all cause existing hyperthyroid state. Now that you have an existing hyperthyroid state all you need is a trigger to flip the patient into a thyroid storm. What are the triggers? Well they include any assault on the body such as trauma, surgery, MI, infection and so on. The trigger can also be a large iodine load to the body such as a CT contrast or amiodarone which contains iodine. Therefore hyperthyroid state plus trigger equals thyroid storm. Remember the signs of symptoms are exaggerated symptoms of hyperthyroidism. Please continue to part two for diagnosis and treatment.