Primary Hypothyroidism, or under-active thyroid gland, may cause a wide variety of symptoms and can affect all bodily functions. Hypothyroidism used to be a laboratory diagnosis. A high TSH blood test signified that one had an underactive thyroid and was placed on synthetic T4 (aka Synthroid). Clinical diagnosis was reserved for people with advanced or severe hypothyroid disease, and even then, if labs were not “abnormal” physicians might have hesitated to treat. Functional medicine physicians are changing this practice by identifying the signs, symptoms, and cause of hypothyroidism early on and starting appropriate treatment.