Hypothyroidism is the medical term for an under-active thyroid gland. Hypothyroid disorders account for about 80% of thyroid disease cases, with the other 20% being hyperthyroid disorders (overactive thyroid). In this book, I address the subjects of symptoms, diagnosis and treatments for hypothyroidism. Also included, is my personal story about developing hypothyroidism, caused by the condition of thyroid autoimmunity called "Hashimoto"s thyroiditis". Due to some difficulties I experienced in having proper testing ordered for my thyroid disorder and afterward being properly treated for it, I became "proactive" in my health care, which I recommend to other patients. I also discuss blood tests and other diagnostic methods for detecting under-functioning thyroid glands and many aspects of thyroid hormone replacement therapy. It is my hope that this book provides the reader with a good general education on the subject of hypothyroidism. This book (approximately 8,010 words in length) 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: Symptoms and Diagnosis of Hypothyroidism CHAPTER TWO: Common Causes of Hypothyroidism CHAPTER THREE: Treatment for Hypothyroidism CHAPTER FOUR: The Pros and Cons of Hypothyroid Treatment CHAPTER FIVE: Book Review for "Hypothyroidism in Childhood and Adulthood" CHAPTER SIX: My Personal Experience with Hypothyroidism