Thread by @BukuEndo

Thyroid #tipsfornewdoctors – sick euthyroidism

The number of TFTs checked in hospital has ⬆️⬆️⬆️ in recent years.

We are always looking for easily reversible thyroid problems as the cause for symptoms, but how often do we find this?

In one study, ~15% of inpatients have mildly abnormal TSH but only 1-2% a true underlying thyroid abnormality.

+ many with abnormal TFTs have no follow up of this anyway!

Acutely unwell patients often have abnormal TFTs – said to be a metabolic compensation.

We called this “sick euthyroid syndrome” or “non-thyroidal illness” (NTI).

This is seen with lots of serious illnesses e.g. sepsis, and also with starvation.

The key feature of NTI = ⬇️⬇️ in T3 (active thyroid hormone)
(this is actually metabolised to “reverse T3” -we don’t measure this)

T4 and TSH can be ➡️ or ⬇️ in NTI
A fall in T4 indicates more severe illness

See image below from Medscape:

So in severe cases with low/N TSH, low T4 and low T3 – this looks like central (secondary) hypothyroidism

As the person recovers, TSH rises to restore normality again

We don’t know if NTI should be treated or not (like a secondary hypothyroidism), so currently this is NOT routine.

It is good practice to ensure patients have their TFTs checked again when they recover (typically at 6 weeks) to ensure there is no underlying abnormality