What Blood Tests Should I Get for Low Energy?

The best blood tests for low energy are TSH, ferritin, vitamin B12, vitamin D, CBC, and fasting glucose. These cover the six most common medical causes: hypothyroidism, iron deficiency, B12 deficiency, vitamin D deficiency, anemia, and blood sugar dysregulation.

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...

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Ferritin

$9

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

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B12

$8

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

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Vitamin D

$22

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

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CBC w/ Diff

$5

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

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Fasting Glucose

$6

Measures blood sugar levels after fasting. Used to screen for diabetes and monitor blood sugar control.

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When to See a Doctor

If your low energy 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

FatigueBrain FogDepressionMuscle Weakness

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Content reviewed for accuracy by the JustLabs editorial team.