Order a thyroid blood test and check your thyroid

A thyroid blood test can help you understand where certain symptoms come from, such as persistent fatigue, weight changes, feeling cold or warm easily, or a shifting mood.

Measuring TSH alone does not always tell you enough, because free T4 and free T3 can change independently. This test measures all three, so the signalling, production and conversion of thyroid hormones all come into view. It remains a snapshot rather than a diagnosis, but it is a concrete starting point.

This test may suit men who:

• experience fatigue, weight changes or sensitivity to cold and want to rule out thyroid-related factors
• have a family history of thyroid conditions
• want to have their thyroid values measured to record a baseline
• simply want to know how their thyroid is doing

You do not need clear symptoms to have your thyroid values measured. Some men do it simply to keep a grip on their health.

This thyroid blood test measures three biomarkers in your blood:

• TSH (thyroid-stimulating hormone) (mu/l, ref: 0.27-4.2): the hormone your pituitary uses to signal the thyroid. An elevated or suppressed TSH may indicate the thyroid is producing too few or too many hormones.
• Free T4 (thyroxine) (pmol/l, ref: 12-22): the unbound, active form of thyroxine, the main hormone your thyroid produces.
• Free T3 (triiodothyronine) (pmol/l, ref: 3.1-6.8): the unbound form of T3, largely converted from T4 in your tissues. T3 is the more active form of thyroid hormone.

Together, these three values may indicate whether your thyroid is producing hormones at the expected level and whether your body converts T4 to T3 adequately. TSH could be elevated while free T4 is still within range, which might suggest the pituitary is working harder to maintain output.

A low TSH with elevated free T4 or free T3 may instead point toward overproduction. The interplay between these markers gives more context than a single value. If you specifically want thyroid antibodies measured, look at the panel for Graves' disease.

For this test, blood is drawn at a certified sample point. There are 700+ locations across the Netherlands, which you choose yourself after ordering.

You arrange this without your GP: you need no referral and pick a location and time that suit you. The draw is done by trained staff and usually takes only a few minutes. Your blood then goes to the lab.

A thyroid blood test can be useful when you have symptoms that might relate to your thyroid, such as unexplained fatigue, weight changes, difficulty concentrating or mood swings. It can also be a handy reference point if you want to track your values over time.

If fatigue is your main complaint, the tiredness panel may also be of interest. Because it is a blood test without a referral, you decide yourself when to start, without first booking a GP appointment.

Your result shows each marker alongside a reference range and a short explanation. Values outside those ranges do not automatically mean something is wrong; they are data points that may warrant further evaluation.

What counts as a healthy value depends on the lab, your age and the time of sampling. Only a doctor can properly interpret your result together with your symptoms and history.

For a thyroid blood test you usually do not need to fast. If you use medication or supplements that can affect your thyroid, such as biotin or thyroid medication, ask your doctor whether that could influence your result.

Try to schedule the draw at a calm moment so your result is as reliable as possible.

Your results are available online within a few working days in your personal dashboard. You log in and view your values whenever it suits you, with a reference range and a clear explanation for each marker.

Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.