TSH levels of 111 hypothyroid people over 70 14 Oct 2025

0-TSH.md

TSH levels of 111 hypothyroid people over 70: 26 % have TSH $\geq$ 4.0

TSH, Thyroid-stimulating_hormone, is measured in blood to determine a suitable dosage of L-thyroxine.

Is TSH 4.0 high ?

Wikipedia TSH gives "reference ranges" of $0.4 - 4.0$ μIU/mL. My family doctor says "Hmm, your 3.9 is pretty high, you should increase your L-thyroxine dosage." How high ? He mumbles about Gaussian distribution 2 σ, top 2 %. (TSH is not Gaussian, log TSH is, but that's irrelevant -- top 2 % is top 2 %.)

TSH levels in one dataset

Kaggle has a dataset of 9172 people, with Age, TSH, hypothyroid ... Clipping this to Age 70 $-$ 100 (not Age 65511) and TSH 0.1 $-$ 10 leaves 1641 people. Of these, 111 are diagnosed hypothyroid. 1/4 of them have TSH >= 4:

TSH >=  4   5    6    7
        26  17   12   7 %

Where does this data come from ? UCI thyroid cites a 1985 paper by Ross Quinlan et al., "An expert system for the interpretation of thyroid assays in a clinical laboratory", but I can't find the original paper.

Should I take more L-thyroxin, or less ❓

Some doctors argue for less in older people, e.g.
Alaeddin et al., Over- and Undertreatment With Levothyroxine: https://di.Aerzteblatt.de/int/archive/article/234792 2023.
Others make lots of money on L-thyroxin, see https://www.transparencymarketresearch.com/levothyroxine-market.html . How to decide ?

... most people are only partly rational -- Bounded rationality

See also

Wikipedia --
Hypothyroidism
Hashimoto's_thyroiditis thyroid gland is gradually destroyed; strong genetic component
TSH Thyroid-stimulating_hormone#Diagnostics reference range of $0.4 – 4.0$ μIU/mL
L-thyroxin == Levothyroxine \

12,000-odd papers on https://scholar.google.com with "allintitle: TSH | thyroid-hormone" since 2015 alone

Can you please point me to newer data

cheers
— denis 2025-10-14 October

_{In God we trust, all others bring data}