Thyroid Function

The thyroid gland plays a role in metabolism, energy regulation, and mood. When thyroid function changes, the effects can be wide-ranging but often subtle. Measuring TSH alongside the active thyroid hormones (Free T4 and Free T3) provides a more complete picture than TSH alone.

This test may be relevant for women who:

• Experience symptoms such as fatigue, weight changes, or sensitivity to temperature
• Have a family history of thyroid conditions
• Want to check thyroid function as part of a general health review
• Have previously had abnormal TSH and want to assess Free T3 and T4 as well

This panel measures three markers:

• TSH (Thyroid Stimulating Hormone): produced by the pituitary gland to regulate thyroid output; typically the first marker assessed in thyroid screening
• Free T4: the unbound form of thyroxine, the primary hormone produced by the thyroid
• Free T3: the unbound form of triiodothyronine, the more biologically active thyroid hormone

TSH acts as a signal from the pituitary to the thyroid. When the thyroid produces less hormone, TSH typically rises to compensate. Measuring Free T4 and Free T3 alongside TSH can help clarify whether the thyroid is responding appropriately. Patterns such as elevated TSH with low Free T4 may suggest reduced thyroid function, while suppressed TSH with elevated Free T4 or T3 may suggest overactivity.

The test requires a blood draw at a certified sample point (afnamepunt). There are over 750 locations across the Netherlands. After placing your order, you can select a convenient location and schedule your visit.

This test may be considered when:

• You want to assess thyroid function beyond a TSH-only test
• You experience symptoms that may be associated with thyroid imbalance
• You have a known thyroid condition and want to monitor function
• You want thyroid data to discuss with your healthcare provider

Each marker is shown with your value and the reference range. The three markers are typically interpreted together. Isolated TSH changes with normal Free T4 and T3 may have different implications than changes across all three. Results should be discussed with a healthcare provider who can interpret them alongside your symptoms.

No specific preparation is needed. No fasting is required. If you take thyroid medication, discuss timing with your healthcare provider.

Your results are typically available within a few working days. Each marker is shown with your value, the reference range, and an explanation. These results can be discussed with your healthcare provider to determine whether further evaluation may be appropriate.