Feeling tired all the time is one of the most common reasons people see their doctor, and you are far from alone. The good news is that fatigue often has causes that show up on ordinary blood tests. While being tired can come from many things, from sleep and stress to nutrition, a few simple lab tests can help your provider check for common, treatable explanations. Here are some tests worth discussing at your next appointment.
Fatigue is common and often checkable
Persistent tiredness is your body's way of asking for attention. Sometimes the answer is lifestyle, and sometimes it is something measurable in your blood, like low iron or an underactive thyroid. The only way to know is to look. That is why talking with your doctor or nurse practitioner is the right first step; they can review your symptoms and history and decide which tests make sense for you.
Tests a provider might consider
There is no single test for tiredness. Instead, providers often start with a small panel that covers the usual suspects. Depending on your situation, they might order:
- Complete blood count (CBC), to check for anemia
- Ferritin and iron studies, to measure your iron stores
- TSH, to check how your thyroid is working
- Vitamin B12, since low levels can cause fatigue
- Vitamin D, which is out of pocket in Ontario unless you meet exception criteria
- A1C or glucose, to screen for blood sugar problems
- Electrolytes, to check your body's balance of minerals
You do not need to memorize this list or request tests by name. Think of it as a starting point for a conversation. Your provider decides what goes on the requisition based on what they find during your visit. They will also weigh other clues, such as your diet, your sleep, medications you take, and any other symptoms, before choosing which tests are worthwhile.
It is also worth remembering that normal results can be reassuring in their own right. If common causes are ruled out, that helps your provider narrow down what else might be going on and decide on the next step, whether that is a change in habits, a referral, or simply checking back in a few weeks.
A note on how ordering works
In Ontario, lab tests must be ordered by an authorized provider, such as a physician or nurse practitioner. You cannot self-order most bloodwork. That is not a hurdle so much as a safeguard: your provider chooses tests that fit your symptoms and can interpret the results in context. Bring up your fatigue honestly and specifically, mention how long it has lasted and anything that makes it better or worse, and let them build the requisition.
Learn more about specific tests
If you want to understand a few of these tests better before your appointment, we have plain-language guides on our site. You can read about ferritin and iron testing, thyroid (TSH) testing, and A1C and blood sugar screening in our test directory. These explain what each test measures and why a provider might order it, so you can walk into your appointment feeling informed rather than overwhelmed.
How to get fatigue bloodwork done at Bio-Test
Once you have a requisition, most bloodwork is walk-in with no appointment, first-come, first-served, at any of our 11 locations across Ottawa-Carleton and Eastern Ontario. Bring your Ontario health card and your requisition. If any test requires fasting, such as a glucose test, your requisition will say so; mornings are busiest with fasting patients. Results are typically ready within about a day and appear in the patient portal and go to your provider. Home collection is available by request for a fee; call 613-789-4242.