Ajax Harwood Clinic
Why am I tired?
Feeling tired all the time is common, and it usually has a real cause that can be found and treated. Sleep problems, low mood, some medicines, alcohol, shift work, and low iron are the most frequent reasons. Thyroid problems, diabetes, low B12, and celiac disease can also cause tiredness. A short list of blood tests can check for most of these. Most people who get tested have normal results, and that is a good sign, not a dead end. Your doctor will also ask about your sleep, mood, stress, and daily habits, since these often matter as much as blood work. If someone suggested checking your iron, that is often a good idea. A normal first round of tests does not mean nothing is wrong. It means the next step is to look closer at sleep, mood, and how your body is coping.
Get help now if
- • You are losing weight without trying
- • You have fevers or drenching night sweats
- • You notice new lumps or swollen glands
- • You have unusual bleeding
- • You have new weakness, numbness, or trouble speaking
- • You have chest pain or shortness of breath
- • Your tiredness is severe and getting worse quickly
Common causes
- • Not enough sleep, or poor-quality sleep
- • Sleep apnea (loud snoring, pauses in breathing)
- • Low mood or anxiety
- • Side effects of some medicines
- • Alcohol or other substances
- • Shift work
- • Low iron, even without anemia
- • An underactive thyroid
- • Diabetes or high blood sugar
- • Low vitamin B12
- • Celiac disease
- • Pregnancy
- • Recovering from a virus, including long COVID
- • ME/CFS (a specific, diagnosable fatigue illness)
- • Menopause
- • Heart, lung, kidney or liver conditions
What your doctor may check
Your doctor will likely ask about your sleep, mood, stress, medicines, alcohol use, and work schedule first. A physical exam checks your heart, lungs, and thyroid, and looks for signs of low iron or other illness. If needed, a small group of blood tests can check your blood count, iron stores, thyroid, blood sugar, and salt and kidney levels. Celiac testing may be added if you have gut symptoms or a family history. These tests are simple and most do not require fasting.
Tests that usually don't help
Some tests are sold for tiredness as "adrenal" or "stress hormone" panels. These include saliva cortisol tests, reverse T3, routine vitamin D, and broad hormone or food panels. These tests have not been shown to explain tiredness. They are not part of standard testing guides. This does not mean your tiredness is not real. It means these tests are unlikely to explain it. Your doctor can suggest tests that are more likely to help.
Get ready for your visit
Our Fatigue check lets you lay out your energy, sleep and mood at your own pace, and gives you a summary to bring to your appointment. Start the Fatigue check →
If this sounds like you
- • Trouble sleeping or staying asleep →
- • Loud snoring or pauses in breathing →
- • Low mood or anxiety →
- • Could it be low iron? →
- • Could it be my thyroid? →
- • Could it be my adrenal glands? →
- • Could it be low B12? →
- • Could it be celiac disease? →
- • Could it be diabetes? →
- • Fatigue that lasts months and worsens with activity (ME/CFS) →
- • Could this be menopause? →
- • Long COVID →
Next steps
Curious what your doctor is weighing up? The clinical page we use for this is open to anyone — it is detailed and written for clinicians, and you are welcome to read it.
Open the clinician reference →Did a naturopath recommend specific tests? Look each one up — what it measures and whether it is usually needed.
Look up a lab test →Want more? Explore the full AHC health library.
Go to ask.ajaxharwoodclinic.com →This is health information and screening — not a diagnosis. Please discuss results with your doctor. In an emergency call 911.