Thyroid: when tiredness is not just tiredness
Exhausted, gaining weight, cold, losing hair, and told the reports are normal. What the thyroid tests actually measure, and what to ask for.
A patient describes months of exhaustion, weight creeping up despite eating less, hair in the comb, feeling cold when nobody else is. Somebody has checked the thyroid, the TSH came back within range, and that was the end of the conversation.
What is being measured
TSH is not a thyroid hormone. It is the signal the pituitary sends to the thyroid, and it is used as a proxy because it responds sensitively to how much hormone is circulating. That makes it a good first test and an incomplete one.
A fuller picture includes free T4 and free T3 — the hormones themselves — and, where the pattern suggests autoimmune thyroid disease, the antibodies. A single TSH in range is not the same as a thyroid that has been properly examined.
The things that imitate it
Tiredness, weight gain, low mood and poor concentration are the least specific symptoms in medicine. The thyroid is one cause among several, and it is worth ruling the others in or out rather than stopping at one normal result.
- Iron deficiency and anaemia, particularly in women
- Vitamin D and B12 deficiency
- Insulin resistance, with its post-meal crashes
- Sleep that is long enough but poor in quality
- Sustained stress, and what it does to cortisol
- Gut problems limiting absorption of what is eaten
If you are already on thyroxine
Keep taking it. Replacement therapy for an underactive thyroid is not something to pause in order to try an alternative, and dose changes belong to the physician who prescribed it, made on the strength of repeat blood tests.
What can be worked on alongside it is everything the prescription does not touch: iron and vitamin D status, gut absorption, sleep, and the metabolic picture that so often sits underneath.
Bring every thyroid report you have, not only the most recent. The direction of travel across several results tells a physician more than any single number.
Questions people ask
- Which thyroid tests should I ask for?
- TSH is the usual first test, but TSH alone can miss part of the picture. A fuller panel adds free T4 and free T3, and thyroid antibodies where autoimmune thyroid disease is suspected. Bring every previous thyroid report you have — the trend over time says more than one result.
- Can thyroid problems be treated naturally?
- Where the thyroid is genuinely underactive and replacement has been prescribed, that medication should be taken as directed and not stopped. Natural treatment at this clinic addresses the nutrition, gut health, sleep and stress around it, alongside the prescription, never instead of it.
- Why do I feel unwell when my reports are normal?
- A normal result rules out one explanation, not all of them. Anaemia, vitamin D deficiency, poor sleep, blood sugar swings, chronic stress and gut problems all produce the same picture of tiredness and low mood, and all are worth checking before tiredness is accepted as unexplained.