Calcitonin and thyroglobulin

Be sure to tell your doctor

• If your thyroid was removed or treated with radioactive iodine
• If you recently had a thyroid needle biopsy. Thyroglobulin can rise for a while after it
• What hormones and medicines you take
• If you take vitamins or supplements with biotin. It can affect the result
• If you are pregnant

How to prepare

• Food. Blood is usually taken in the morning on an empty stomach: 8 to 12 hours without food. Plain water is fine. Check with the lab.
• The day before. For 24 hours: no alcohol and no hard workouts. Try not to smoke in the morning.
• Medicines. Do not stop anything on your own. Tell your doctor what you take. They will decide if anything needs to change before the test.
• Clothing. A sleeve you can easily roll up above the elbow.

What to bring

• Your referral or list of tests
• Your ID
• Past results of these tests. Comparing them matters
• Ultrasound reports and your hospital discharge summary after surgery, if you have them

How it goes

1. You sit down and rest your arm on the armrest
2. A band is tied above your elbow, and you are asked to clench your fist a few times
3. The skin is wiped with antiseptic
4. A quick prick. Blood fills the tubes in a few seconds
5. The needle comes out, and a cotton pad is pressed on the spot

What you'll feel

• A quick prick, like a pinch
• Sometimes slight dizziness. Tell the nurse, and they will help you lie down

Afterwards

• Press the cotton pad for 3 to 5 minutes
• You can eat after the test
• Try to repeat the test at the same lab. That makes results easier to compare