Top 5 Lab Tests for Fatigue | Discover the Root Cause of Exhaustion
top of page
Sage_Logo_Purple Letters (2).png

The Top 5 Lab Tests You Need To Figure Out Chronic Fatigue (and start feeling like yourself again)

Writer: Sage Integrative Medicine ClinicSage Integrative Medicine Clinic
Feb 223 min read

Why Am I Always Tired? Expert Testing Insights from Dr. Angila Jaeggli

Feeling exhausted despite "normal" bloodwork results? Many patients are told that fatigue is just a part of aging or stress, but persistent exhaustion is not normal. At Sage Integrative Medicine Clinic, we understand that energy loss has deeper causes—and comprehensive testing can reveal what’s truly going on in your body.

Here are the top 5 lab tests that I, Dr. Angila Jaeggli, recommend when evaluating unexplained fatigue. These tests help uncover hidden imbalances and deficiencies, providing a clear roadmap to reclaim your energy.

Top 5 Lab Tests for Fatigue

1. TSH (Thyroid-Stimulating Hormone) – Uncover Hidden Thyroid Issues

The thyroid gland plays a vital role in metabolism, energy levels, and muscle repair. Even if standard results appear normal, an optimized TSH level should be under 2.5.

Why Test for TSH?

  • Detects early thyroid dysfunction

  • Helps identify autoimmune thyroid conditions like Hashimoto’s thyroiditis

  • Assesses overall thyroid hormone balance

If your TSH is above 2.5, further thyroid hormone testing (including T3, T4, and thyroid antibodies) may be necessary to identify underlying imbalances.

2. Cortisol Levels – Assess Adrenal Health and Energy Reserves

Cortisol, secreted by the adrenal glands, is essential for maintaining stamina throughout the day. Testing morning cortisol levels can reveal signs of adrenal fatigue or stress-related hormone imbalances.

Why Test Cortisol?

  • Detects adrenal fatigue and stress overload

  • Identifies irregular cortisol patterns (common in night shift workers)

  • Guides treatment for energy restoration

Cortisol should be tested in the morning (ideally via saliva or blood test) when levels are naturally at their peak.

3. Homocysteine – Assess Vitamin B Deficiency and Methylation Issues

Elevated homocysteine levels often indicate deficiencies in essential B vitamins: B6, B9 (folate), and B12—key nutrients for energy metabolism.

Why Test Homocysteine?

  • Detects vitamin B deficiencies

  • Evaluates methylation efficiency (critical for detoxification and energy production)

  • Identifies potential cardiovascular and cognitive risks

An optimal homocysteine level should be around 7.0. Levels above this threshold suggest a need for targeted B-vitamin supplementation.

4. Iron and Ferritin – Check for Hidden Anemia and Iron Deficiency

Even without anemia showing up on a Complete Blood Count (CBC), low iron or ferritin can contribute to chronic fatigue.

Why Test Iron and Ferritin?

  • Measures oxygen transport efficiency

  • Detects iron deficiency before anemia develops

  • Prevents iron overload, which can damage heart and brain cells

Ideal ferritin levels should be under 70—higher levels can be toxic and may indicate conditions like Hereditary Hemochromatosis.

5. Epstein-Barr Virus (EBV) – Identify Viral Triggers of Chronic Fatigue

The Epstein-Barr Virus (EBV), responsible for mononucleosis, can remain dormant and reactivate under stress or poor immune function—leading to persistent fatigue.

Why Test for EBV?

  • Identifies chronic viral reactivation

  • Explains symptoms like lethargy, achy muscles, and flu-like fatigue

  • Helps develop immune-supportive treatment plans

Recommended tests include EBV IgG Antigen, EBV IgG Early Antigen, and, for recent infections, EBV IgM Antibodies.

Bonus Tests for Deeper Energy Insights

1. Testosterone Levels (For Men)

Low testosterone can lead to fatigue, depression, muscle loss, insomnia, and mood swings. Testing both Free and Total Testosterone helps establish a baseline for future health optimization.

2. Methylation Panel + MTHFR Gene Testing

Methylation is crucial for detoxification and energy production. Genetic mutations in MTHFR can impair your body’s ability to process B vitamins and detox efficiently.

  • Get your raw DNA data from Stratagene.org or GeneticGenie.org

  • Advanced methylation testing from Genova Labs provides insight into detox pathways and energy metabolism

What Do These Tests Reveal?

These lab tests offer a starting point for uncovering the hidden causes of fatigue. They assess hormone levels, nutrient deficiencies, viral triggers, and genetic detox pathways—essential factors that could be draining your energy.

At Sage Integrative Medicine Clinic, we offer personalized evaluations and treatment plans to help restore your energy and vitality.

Join Our Upcoming Course: Beating Chronic Fatigue Naturally

In 2025, Dr. Angila Jaeggli will be launching a course focused on overcoming chronic fatigue through naturopathic and integrative methods. This program will cover:

  • Uncovering hidden fatigue triggers

  • Developing a sustainable, personalized energy recovery plan

  • Incorporating lifestyle changes for long-term vitality

Join our newsletter at sagemedclinic.com for course updates and expert health tips.

Ready to Reclaim Your Energy?

Have questions? Contact us today to schedule an appointment or learn more about our personalized fatigue evaluations.

Sage Integrative Medicine ClinicEmail: info@sagemedclinic.comWebsite: sagemedclinic.com

Connect With Us

 
 
 
bottom of page