Still Tired? Here's What Your Body Might Actually Be Telling You

The most overlooked root causes of persistent fatigue in women and the lab tests that can finally give you real answers.

If you've been told your labs are normal but you still can't get through the day without crashing, you're not imagining things, and you're not alone. This is one of the most common experiences women bring to my practice, and one of the most frustrating: doing everything right, yet still feeling depleted.

The problem is rarely a lack of trying. It's that standard bloodwork is designed to rule out disease, not to understand how your body is actually functioning. A thyroid marker, TSH, in the "normal" range doesn't tell us how your thyroid is converting hormones. A hemoglobin within reference range doesn't tell us whether your iron stores have bottomed out. Lab testing results need context, and context requires looking at the full picture.

Here's what I assess when a patient comes to me with persistent fatigue, and why each piece matters.

Root Causes I Commonly See in Practice

HPA Axis Dysregulation - Burnout

• Your Hypothalamic-Pituitary-Adrenal (HPA) axis governs your stress response and cortisol rhythm. When it's been running on high for too long, cortisol patterns become dysregulated — too high, too low, or poorly timed across the day. This is what drives that distinct "wired but tired" feeling: exhausted but unable to switch off, crashing in the afternoon, waking unrefreshed no matter how many hours you sleep.

Thyroid Dysfunction

• The thyroid regulates your metabolic rate, essentially, how your body makes and uses energy. Even subtle low functioning can produce significant fatigue, brain fog, cold intolerance, and mood shifts. The catch is that following reference ranges for the standard Thyroid Stimulating Hormone (TSH) alone often misses it. Using finer thresholds and assessing the rest of the thyroid picture including "Free T3", "Free T4", and thyroid antibodies can reveal patterns that a single marker may miss.

Low Iron & Ferritin

• Iron deficiency depletes energy long before anemia appears on your bloodwork. Ferritin, your iron storage protein, is often a big piece. Many women are told their iron is fine when their ferritin is significantly low, and that gap makes all the difference. There can also be factors that impact the accuracy of ferritin assessments and running complete iron panels beyond ferritin can often be helpful to isolate hidden deficiencies of iron.

Hormonal Health

• Estrogen, progesterone, and testosterone all influence energy, sleep quality, and motivation, across every life stage, from PMS and postpartum to perimenopause. These aren't "just hormonal" symptoms. They're whole-body signals that deserve a comprehensive look, not a dismissal.

Blood Sugar Dysregulation

• Unstable blood glucose is one of the most under-appreciated drivers of fatigue, and it doesn't require a diabetes diagnosis. Glucose swings throughout the day cause energy crashes, afternoon slumps, irritability, and carbohydrate cravings. Chronic stress makes this worse by directly impacting insulin sensitivity.

Nutritional Deficiencies

• Vitamin B12 and Vitamin D are critical for energy production and nervous system function. These nutrients are frequently low in women, especially those who are postpartum, experience chronic digestive issues, are vegetarian, or managing chronic stress.

Gut Health & Inflammation

• Even a nutrient-rich diet won't fully support your energy if absorption is impaired. Chronic gut inflammation, intestinal permeability, or dysbiosis can all contribute to fatigue. This can occur both through poor nutrient uptake and through systemic inflammatory signals that are metabolically expensive for your body to manage.

  
  

In most patients presenting with fatigue, we find more than one contributing factor. A woman dealing with burnout is often also navigating low ferritin, disrupted hormones, and poor sleep. Addressing fatigue effectively requires an all-encompassing approach.

The Lab Tests I Use and Why

Testing is most valuable when it's targeted and interpreted in context. Below are the panels I commonly consider when working with women experiencing persistent fatigue. Not every patient needs every panel, your history and symptoms guide what we prioritize.

Thyroid Function

• First morning TSH, Free T3 & Free T4: Full thyroid output and hormone conversion

• TPO & Thyroglobulin Antibodies: Detects Hashimoto's (thyroid autoimmune) activity even when TSH appears normal

Iron and Oxygen Delivery

• Ferritin: Iron storage; often the first to drop, long before anemia shows on a CBC

• Serum Iron, TIBC & CBC: Current iron availability, binding capacity, and red blood cell status

HPA Axis and Stress Response

• Salivary Cortisol (4-point): This is an at home test that measures cortisol at four points across the day, revealing the full diurnal rhythm. While AM Cortisol can be a helpful initial insight, salivary cortisol testing can be far more informative than a single morning reading.

• DHEA-S: Adrenal reserve marker; commonly low in burnout and prolonged stress

Sex Hormones

• Estradiol & Progesterone: Cycle-phase assessment; imbalances directly affect sleep quality, mood, and energy

• Free Testosterone: Low levels contribute to fatigue, low motivation, and reduced stamina in women

• FSH, LH: Ovarian function and hormone availability, especially relevant in perimenopause

Nutritional Status

• Vitamin D (25-OH): Supports immune function, mood regulation, and energy. Deficiency is extremely common, especially in Canada.

• Vitamin B12: Essential for neurological function and red blood cell production. Frequently low in women with chronic digestive concerns, are vegetarian, postpartum, or on certain medications.

Blood Sugar and Inflammation

• Fasting Glucose, Insulin & HbA1c: Together these reveal insulin resistance and blood sugar patterns before disease develops

• ESR and CRP : Markers of systemic inflammation.

A Note On Testing:

I work with each patient to prioritize what's most clinically relevant given their history and symptoms, so we're not ordering everything indiscriminately, but we're also not leaving important gaps unaddressed.

What Happens After We Have Answers

This is where the work, and the relief, really begins. Once we have a clearer picture of what's driving your fatigue, we build a plan that's actually targeted to you. That might mean supporting thyroid conversion with specific nutrients, replenishing ferritin through diet and supplementation, regulating blood sugar through meal timing and addressing factors that might be impacting insulin regulation or beginning a graduated approach to stress recovery that includes nervous system support and adaptogenic herbs.

What matters most is that you're no longer guessing, you have a map, and we move forward together from there. Individualized care involves adjusting as your health evolves, not following a rigid protocol designed for someone else.

If you've been living with exhaustion that no one has been able to fully explain, please know this: your body is not failing you, it's communicating, and with the right assessment, those signals finally start to make sense.

Ready to Find Your Answers?

Book an initial visit with me at The Wellness Lab and we'll take a comprehensive, root-cause look at what's driving your fatigue, together.

Book with Dr. Andriana Here

Dr. Andriana Setnik, ND is a licensed naturopathic doctor registered with the College of Naturopaths of Ontario (CONO) and a member of the OAND and CAND. This post is for educational purposes and does not constitute medical advice. Please consult a qualified health professional for personalized care.