What Blood Tests Should I Get for Fatigue?

The best blood tests for fatigue are TSH, ferritin, vitamin D, CBC, and a comprehensive metabolic panel. These cover the most common medical causes of persistent tiredness, including hypothyroidism, iron deficiency, vitamin D deficiency, anemia, and blood sugar imbalances.

Possible Causes

HypothyroidismAnemiaIron DeficiencyVitamin D DeficiencyType 2 Diabetes

Recommended Tests

TSH

$8

Measures thyroid-stimulating hormone to evaluate thyroid function. TSH is the most sensitive marker for detecting thyroi...

Order Test

Ferritin

$9

Measures iron storage protein. Best indicator of total body iron stores.

Order Test

Vitamin D

$22

Measures vitamin D status. Deficiency is common and linked to bone health, immune function, and mood.

Order Test

CBC w/ Diff

$5

Comprehensive blood cell analysis including red cells, white cells, platelets, and white cell differential.

Order Test

CMP

$10

Measures 14 substances including glucose, electrolytes, kidney and liver function markers.

Order Test

B12

$8

Measures B12 levels essential for nerve function, DNA synthesis, and red blood cell formation.

Order Test

When to See a Doctor

If your fatigue is severe, rapidly worsening, or accompanied by alarming symptoms (chest pain, shortness of breath, high fever), seek immediate medical attention. Blood tests are a valuable first step, but they don't replace evaluation by a healthcare professional.

Frequently Asked Questions

Related Symptoms

Low EnergyBrain FogHair LossDepression

Related Articles

Thyroid Function Tests Without Insurance

How to get TSH, Free T4, and Free T3 tested affordably without insurance coverage.

Vitamin D Test Cost: Self-Pay Options

How much a vitamin D test costs without insurance and where to find the best price.

What Lab Tests Should I Get for Fatigue?

The essential blood tests to identify thyroid, iron, and vitamin causes of tiredness.

Content reviewed for accuracy by the JustLabs editorial team.