How are thyroid hormone levels assessed? Elizabeth Tracey reports


Thyroid hormone is one of the most commonly prescribed medicines to older people, but a Johns Hopkins study shows that some people have levels that are too high, and this puts them at risk for dementia. Jennifer Mammen, an endocrinologist and one of the study’s authors, describes how the hormone is measured.

Mammen: The pituitary is the driver of the thyroid car so the TSH works like the pressure on the gas pedal, so it's the opposite of the thyroid hormone level. When your thyroid hormone level is too high the TSH will be low because your pituitary has the brake on, trying to rein in the thyroid hormone level. And so if your TSH is low that means you're on too much thyroid hormone and the dose needs to be reduced, and that's what we were measuring in this study. We were looking at when people have low TSH did they have an increased risk of dementia.  :34

Mammen notes these are routine measurements, so get them checked. At Johns Hopkins, I’m Elizabeth Tracey.