What Do Dangerously High TSH Levels Indicate?

By Staff WriterLast Updated Mar 27, 2020 12:25:19 PM ET

Very high levels of Thyroid Stimulating Hormone indicate an underactive thyroid gland, or hypothyroidism, according to EndocrineWeb. High levels of TSH, which is diagnosed by blood tests, mean that the body is attempting to coax the thyroid gland into producing more of the thyroid hormone.