Thread by @BukuEndo

Ok #MedStudentTwitter so we've got the basics of endocrinology now.

Keep reading for how that helps us understand hormone test results ⬇️⬇️

When faced with endocrine results, we usually start with the EFFECTOR HORMONE – is this normal/abnormal? ✅❎

If abnormal, we then look to the 2ry controlling hormone – has this made an APPROPRIATE COMPENSATION?

This is 🔑 with endocrinology - an "appropriate compensation" often puts the 2ry hormone out of the "normal" reference range.

This is what should happen if the control centre is working properly!

So is it "appropriate" NOT is it "normal" is the Q we ask!

i.e.
If 1ry hormone is ⬇️, 2ry hormone should be ⬆️ (“make more”)

If 1ry hormone is ⬆️, 2ry hormone should be ⬇️ (“make less”)

If not, the 2ry hormone may be the problem

Some examples using the thyroid:

T4 ⬇️
TSH ⬆️
= primary hypothyroidism (e.g. Hashimoto’s thyroiditis)

T4 ⬇️
TSH ⬇️ OR ➡️ (i.e. not “appropriately high”)
= secondary hypothyroidism (e.g. pituitary lesion)

Easy, right?!