TSH, the thyroid signal Thyroid Stimulating Hormone (TSH)
The message your brain sends to tell your thyroid to work harder.
Also printed asTSH · Thyrotropin · TSH Ultrasensitive · TSH 3rd Generation
What it measures
The pituitary gland telling your thyroid how hard to work.
Sets your whole metabolic rate - and because thyroid hormone controls how fast the liver clears LDL, it moves your cholesterol too.
Why it matters for how long you stay well
A slow thyroid quietly raises cholesterol, slows the heart and drains energy for years before anyone names it, and it is one of the most correctable findings on the whole panel.
How it shows up in daily life
When the thyroid is slow you may feel cold, heavy, constipated and tired in a way sleep does not fix, and hair may thin.
High and low readings
When it reads high
The brain is shouting; the thyroid may be underperforming.
When it reads low
The brain has gone quiet; the thyroid may be overactive.
What moves it
Daily life
- iodine intake, including iodised salt
- selenium intake
- recent illness or a very low-calorie phase
- pregnancy
- smoking
Medicines known to shift it
- thyroid hormone replacement (lowers it)
- steroids (lower it)
Listed so a result can be read in context. It is not advice to start, stop or change any medicine; that decision belongs with your physician.
Read it with
Markers that move this one, or that this one moves. One number read alone can mislead.
- LDL, the carrying cholesterolKnown mechanism
As this rises, LDL rises with it
Your thyroid sets the speed at which your liver pulls LDL out of the blood. When the gland idles, the clearing slows and LDL piles up.
- Total cholesterolKnown mechanism
As this rises, Total cholesterol rises with it
The same slowdown does not stop at LDL. Everything the liver is meant to collect backs up behind it, so the total drifts up as well.
- ApoB, the particle countObserved association
As this rises, ApoB rises with it
ApoB counts the particles your liver has not yet collected. A slow thyroid means fewer collections, so the count creeps up alongside the cholesterol.
- Triglycerides, blood fatsObserved association
As this rises, Triglycerides rises with it
A slow thyroid also slows the breakdown of blood fats. They sit in the blood longer than they should, so triglycerides drift up with everything else.
Common questions
What does Thyroid Stimulating Hormone measure?
The pituitary gland telling your thyroid how hard to work. Sets your whole metabolic rate - and because thyroid hormone controls how fast the liver clears LDL, it moves your cholesterol too.
What does a high TSH result usually mean?
The brain is shouting; the thyroid may be underperforming.
What does a low TSH result usually mean?
The brain has gone quiet; the thyroid may be overactive.
What is the usual reference range for TSH?
A broad adult reference band is 0.4–4.5 µIU/mL. Labs differ, so read your result against the band printed on your own report.
Educational only, not a diagnosis. A single number means little without your history and the rest of your panel, so discuss your own results with your physician.
Typical adult reference band
- Adults
- 0.4–4.5 µIU/mL
Labs differ. The band printed on your own report is the one that applies to your result.
Reported in µIU/mL, mIU/L
Ageing relevance
3/5
A moderate ageing association; used in clinical longevity panels.
Worth knowing
A high number means your brain is shouting at the gland, so this result moves opposite to how the thyroid is performing.
Related reading
Have a report with this marker on it? Read it in context.
Upload it to Oraia, our health-intelligence tool, for a plain-language read of your markers that a Genoryx doctor can review.
Your biological age is a number you can measure.
Start with the 400+ parameter entry assessment and a 60-minute physician consultation at either Hyderabad clinic. Open seven days, 11 AM to 9 PM.
Book a consultation