What Blood Tests Should I Get for Unexplained Weight Gain?

The best blood tests for unexplained weight gain are TSH, fasting insulin, fasting glucose, HbA1c, a lipid panel, and cortisol. Hypothyroidism is the leading hormonal cause. These tests also detect insulin resistance, prediabetes, and metabolic imbalances that drive weight gain unrelated to diet.

Possible Causes

HypothyroidismInsulin ResistancePCOS (Polycystic Ovary Syndrome)Type 2 DiabetesAdrenal Fatigue

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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Free T4

$8

Measures the unbound, active form of the thyroid hormone T4. Helps assess thyroid function and diagnose thyroid conditio...

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Fasting Insulin

$14

Measures fasting insulin levels to assess insulin resistance and metabolic health. Important for early detection of diab...

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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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HbA1c

$7

Measures average blood sugar over the past 2-3 months. Key marker for diabetes management and prediabetes screening.

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Lipid Panel

$7

Standard cholesterol panel including total cholesterol, HDL, LDL, and triglycerides. Essential for cardiovascular risk a...

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Total Cortisol

$13

Measures total cortisol levels to assess adrenal function and stress response.

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When to See a Doctor

If your unexplained weight gain 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

FatigueCold IntoleranceDepressionBloating

Related Articles

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

How to Get an A1C Test Without a Doctor

Order an HbA1c test online for $7 to screen for prediabetes and monitor blood sugar.

Glucose and Metabolic Panel: What to Order

Which metabolic tests to order for blood sugar screening and diabetes monitoring.

Content reviewed for accuracy by the JustLabs editorial team.