Had a thyroid blood tests one came up high an one l ow iv got to retake a test what does this mean?

Which is which?: If one of the thyroid function tests is high and one is low, depending on whether it is TSH or free t4, you could either have an over active or under active thyroid. It's also possible that your next set could be normal. Without more detail it isn't possible to respond more specifically. Having thyroid antibodies and possibly TSH receptor antibody testing may help elucidate.