Pacific · Thyroid Tests
Thyroid Tests in California
Thyroid Tests is a laboratory test you can request directly. Thyroid tests measure how well your thyroid gland is working. They are simple blood tests that can be ordered without a doctor's referral.
Lab requirements in California
Here is what you need before ordering and completing the Thyroid Tests in CA. Review each item and confirm the details with the collection lab.
- Physician's order
- Included. A physician's order is required for lab testing and is provided for you by our partner's physicians — no referral from your own doctor is needed.
- Fasting
- Fasting is required for this test — follow the collection lab's instructions.
- Preparation
- Preparation instructions can vary depending on the specific tests ordered and the laboratory performing them. Always follow the collection lab's instructions regarding fasting, timing, and…
- Sample & visit
- A blood and/or urine sample is collected; the visit usually takes about 10 minutes.
- Identification
- Bring the lab requisition form from your account. The collection lab may also ask for a government-issued photo ID.
- Turnaround
- 1-3 business days
- Availability
- Our partner lab does not serve ND, RI, NY, NJ, MD or HI. Confirm availability for your location with the collection lab.
Before you go
- Order your test before visiting a lab, then use the requisition form in your account.
- Print the requisition form, or fax it to the lab directly from your account.
- No scheduling is needed — visit the collection lab during its normal business hours.
- A blood and/or urine sample is collected; the visit usually takes about 10 minutes.
- Bring a government-issued photo ID in case the lab requests it.
- Results are posted to your secure account within 1–3 business days.
Requirements are summarized from our partner lab's published policies. Preparation and availability can change — confirm current instructions with the collection lab before your visit.
What this test is
Thyroid tests are blood tests that check the levels of thyroid hormones and related substances in your body. These tests help evaluate whether your thyroid is overactive, underactive, or functioning normally. They are commonly used to screen for thyroid disorders or to monitor treatment.
What it measures
- TSH (Thyroid-Stimulating Hormone) — reflects how well the thyroid is being stimulated by the pituitary gland
- Free T4 (Thyroxine) — measures the amount of active thyroid hormone available to the body
- Free T3 (Triiodothyronine) — measures the amount of active thyroid hormone that regulates metabolism
- Total T4 — measures both bound and unbound thyroxine in the blood
- Total T3 — measures both bound and unbound triiodothyronine in the blood
- Thyroid Peroxidase Antibodies (TPOAb) — detects antibodies that may indicate an autoimmune thyroid condition
- Thyroglobulin Antibodies (TgAb) — detects antibodies that may be associated with thyroid autoimmunity
What the test involves
A healthcare professional collects a small sample of blood from a vein in your arm using a needle. The sample is then sent to a laboratory for analysis.
Why it is often ordered
A clinician may order thyroid tests if you have symptoms such as fatigue, weight changes, or heart palpitations that could be related to thyroid function. They may also be ordered to monitor a known thyroid condition or to check the effectiveness of thyroid medication.
Preparation
Preparation instructions can vary depending on the specific tests ordered and the laboratory performing them. Always follow the collection lab's instructions regarding fasting, timing, and any medications.
How results are reported
Results are typically reported as numerical values for each thyroid marker, along with a reference range. Reference ranges can differ between laboratories, so your results should be interpreted in the context of the lab that performed the test.
Before you go
- Whether fasting is required before your test
- If any medications you take could affect the results
- The specific tests included in your panel
Cities
Thyroid Tests in California communities
Choose your city for local context and to order this test.