Thyroid storm is caused by too much thyroid hormone in the body. Thyroid storm is a medical emergency. Precipitating factors for thyroid storm include infections, thyroid surgery, stopping thyroid medications, pregnancy, heart attack, and cardiac emergencies. Symptoms of thyroid storm include palpitations, increased body temperature, chest pain, anxiety, weakness, disorientation, and heart failure. Thyroid storm is a medical emergency, and anyone experiencing symptoms of thyroid storm should proceed to an emergency department promptly.