The majority of patients with both hypothyroidism (under-active thyroid) and hyperthyroidism (overactive thyroid) are experiencing autoimmune diseases that cause these conditions. When autoimmune thyroid disease results in hypothyroidism, the term for the disease is "Hashimoto's thyroiditis." When the autoimmune disease of the thyroid causes hyperthyroidism, it is called "Grave's Disease." Thyroid antibodies attack key proteins in the thyroid gland and in some cases, stimulate production of excessive amounts of hormone. These killer cells that are manufactured by the immune system become confused for reasons yet to be fully understood by medical science and they begin to identify thyroid cells as threats in the body. As they attack these cells, the thyroid gland becomes damaged, resulting in inflammation, enlargement of the gland (goiter) and thyroid hormone imbalances. This book is not intended to be an extensive manual but is intended to contain information most often sought by laypersons on the subject. CONTENTS: CHAPTER ONE: Facts about Thyroid Antibodies CHAPTER TWO: Do Thyroid Antibodies Cause Symptoms Apart From Abnormal Hormone Levels? CHAPTER THREE: Hereditary Autoimmune Thyroid Disease CHAPTER FOUR: Epstein-Barr Virus a Cause of Autoimmune Thyroid Disease? CHAPTER FIVE: Hashimoto's Encephalopathy Rare but Serious CHAPTER SIX: My Own Experience with Thyroid Antibody Related Symptoms CHAPTER SEVEN: Autoimmune Hypothyroidism (Hashimoto's) a Cause of Chronic Fatigue Syndrome CHAPTER EIGHT: Doctors Should Test for Thyroid Antibodies CHAPTER NINE: At What Point Does Thyroid Autoimmunity Cause Hypothyroidism? CHAPTER TEN: Medical Research Agrees: Thyroid Autoimmunity Contributes to Symptoms