Hormones
Thyroid (TSH, T3, T4) and PSA.
Thyroid-stimulating hormone (TSH)
The main test to check whether the thyroid is working properly. Preparation: no fasting; if you take thyroid medication, take it after the sample.
Triiodothyronine (T3)
One of the hormones made by the thyroid. Preparation: no fasting.
Total thyroxine (T4)
The main thyroid hormone, measured as a total. Preparation: no fasting.
Free thyroxine (FT4)
The active part of T4, giving a more precise reading of thyroid function. Preparation: no fasting.
Prostate-specific antigen (PSA)
A blood test to check the prostate in men, as part of their checkup. Preparation: no fasting; avoid sexual activity and cycling for 48 hours before.
Before your test
Fasting means no food or sugary drinks; plain water is fine. Bring an ID and, if you have one, your doctor’s order. Tell us what medications you take. Don’t see your test? Call us and we’ll tell you if we offer it and how to prepare.