What happens if your thyroid glands are removed and you take no synthetic thyroid medicine?

They thyroid hormones are directly involved with the metabolism of the whole body. Excessive or reduced amounts of these hormones will adversely effect organ and body functions. Abnormally low thyroid hormones (hypothyroidism) lead to decreased metabolism which basically means the body slows down. This leads to eventual organ failure and possible death. Some signs of hypothyroidism are extreme fatigue, hair loss and red/purple blotches on the skin. The reversal of these symptoms by the use of synthetic hormones, such as synthroid, is dramatic.