If your provider has ordered a TSH or thyroid test, you can have it done quickly and close to home. At Bio-Test Laboratory, serving Ottawa-Carleton and Eastern Ontario since 1971, thyroid bloodwork is a walk-in test at any of our locations with a valid requisition. Here is what these tests look at and how to get yours drawn without the hassle of an appointment.
What is TSH?
TSH stands for thyroid-stimulating hormone. It is made by the pituitary gland in your brain, and its job is to signal the thyroid, a small gland in your neck, to produce thyroid hormones. Measuring TSH is the most common first step in checking thyroid function, because it reflects how hard your body is working to keep those hormones in balance. A single blood sample is all that is needed.
Why TSH gets ordered
Providers order TSH to screen for or monitor thyroid conditions. It is often the starting point when the thyroid is either underactive or overactive, and it is also used to keep an eye on people already being treated for a thyroid problem or taking thyroid medication. Because it is such a useful screening marker, TSH frequently appears on routine bloodwork panels alongside things like a complete blood count and cholesterol. It is also commonly checked during pregnancy and when a provider is adjusting a medication dose, since even small changes in thyroid function can affect how you feel day to day.
T3, T4, and the thyroid panel
TSH is often just the first look. Depending on your result and your symptoms, your provider may add other tests to build a fuller picture:
- Free T4 (thyroxine), a main hormone the thyroid produces
- Free T3 (triiodothyronine), the more active thyroid hormone
- Thyroid antibodies, which can point to autoimmune thyroid conditions
Together these are sometimes called a thyroid panel. Your provider decides which pieces you need, and they will all be listed on your requisition.
No fasting needed for TSH
Good news for timing: a TSH test does not require fasting, so you can eat and drink normally beforehand. That means you are not tied to an early-morning visit and can come in when it suits you. If your provider has combined your thyroid test with something that does need fasting, such as a glucose or certain metabolic tests, your requisition will indicate whether fasting is required, so follow what it says.
Symptoms that may prompt testing
People are often sent for thyroid testing when they have symptoms that can be linked to thyroid function. These vary from person to person and are not proof of a thyroid problem on their own, since many of them overlap with everyday stress or other conditions, but they are worth mentioning to your provider. Common ones include:
- Unexplained fatigue or low energy
- Weight changes that are hard to explain
- Feeling unusually cold or unusually warm
- Changes in heart rate or palpitations
- Mood changes, or trouble with concentration
- Changes in skin, hair, or bowel habits
For a deeper explainer on underactive and overactive thyroid, including hypothyroidism and hyperthyroidism, see our thyroid health article. You can also look up individual thyroid tests in our test directory.
Getting your thyroid test at Bio-Test
With a requisition, you can walk in for a TSH or full thyroid panel at any of our 11 locations across Ottawa-Carleton and Eastern Ontario, no appointment needed and no fasting required for TSH. Bring your Ontario health card and requisition, and come in whenever suits you, since mornings are our busiest time. Prefer a set time? Book online through our patient portal. Homebound patients can request an at-home visit for a fee by calling 613-789-4242.