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Your thyroid and your blood
The thyroid regulates your metabolism, energy and weight. If it works too slowly or too quickly, you can see it in your blood. Below you read which blood values give insight and when testing is useful.
What does the thyroid do?
The thyroid produces hormones that drive your metabolism: how fast your body uses energy. An underactive thyroid may relate to fatigue, weight gain and feeling cold; an overactive thyroid to restlessness, palpitations and weight loss. Symptoms are not specific, which is why blood testing is valuable.
Which blood values give insight?
TSH is the pituitary hormone that drives the thyroid and the most sensitive first marker. Free T4 is the active thyroid hormone itself. The combination gives the most complete picture. Your result is always assessed against the laboratory's reference range, not fixed numbers.
When is testing useful?
With persistent fatigue, unexplained weight change, hair loss or a thyroid condition in the family, targeted testing can provide reassurance. If you use thyroid medication, please let us know so the doctor can adjust the interpretation.
Relevant blood values
Frequently asked questions
What is the difference between TSH and Free T4?
TSH comes from the pituitary gland and drives the thyroid. Free T4 is the thyroid hormone itself in its active form. Together they give the most complete picture of thyroid function.
Do I need to fast for thyroid testing?
Fasting is not required for TSH and Free T4. Preferably take the sample at a calm time of day.
What if my values are abnormal?
Our doctor provides explanation and context with your result. For significantly abnormal values we proactively make contact. Always discuss the result with your (GP) doctor.
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