---
title: "Which blood tests are used for unexplained weight loss?"
type: symptom
url: "https://www.test-well.com/symptoms/unexplained-weight-loss"
symptom: Unexplained weight loss
aliases:
  - losing weight without trying
  - weight loss blood test
reviewed_at: 2026-09-06
review_status: reviewed
date_published: 2026-09-05
lab_fee_usd: 6
---

# Which blood tests are used for unexplained weight loss?

> Losing weight without trying deserves a prompt, broad look: an overactive thyroid, diabetes, celiac disease and chronic inflammation are the common testable causes. The initial set is TSH with Free T4, hemoglobin A1c and glucose, a CBC, a comprehensive metabolic panel, CRP and a celiac screen — and a clinician visit alongside, because this symptom warrants one.


## When should you see a clinician instead of ordering a test?

- Loss of more than about 5% of body weight in 6–12 months without trying — see a clinician
- Weight loss with night sweats, fever, a persistent cough, blood in stool or trouble swallowing — see a clinician promptly

## Why these tests for unexplained weight loss?

Hyperthyroidism speeds metabolism (low TSH, high Free T4). New or uncontrolled diabetes causes weight loss with thirst and urination. Celiac disease and other malabsorption reduce nutrient uptake, and chronic inflammation or infection raises CRP and shifts the CBC.

Blood tests narrow the field quickly, but unexplained weight loss is one of the symptoms where a clinician should be involved early rather than after several rounds of self-ordered tests.

## Which conditions do these tests help evaluate?

- [Thyroid Problems](https://www.test-well.com/conditions/thyroid-problems) — TSH, Free T4/T3 and antibodies to evaluate an under- or over-active thyroid.
- [Diabetes & Blood Sugar](https://www.test-well.com/conditions/diabetes-screening) — A1c, fasting glucose and insulin to screen for prediabetes and diabetes.
- [Celiac Disease](https://www.test-well.com/conditions/celiac-disease) — Celiac antibody testing and the markers used to screen for gluten-related disease.

## Which tests, and what do they cost?

| Test or panel | Type | Price | All-in (one item + $6 fee) | Fasting | Results |
| --- | --- | --- | --- | --- | --- |
| [General Wellness Panel](https://www.test-well.com/tests/general-wellness-panel) | Panel (4 tests) | $89.99 | $95.99 | Yes | 1–3 business days |
| [Complete Thyroid Panel](https://www.test-well.com/tests/thyroid-complete-panel) | Panel (4 tests) | $109.99 | $115.99 | No | 3–7 business days |
| [Gut Health Panel](https://www.test-well.com/tests/gut-health-panel) | Panel (5 tests) | $129.99 | $135.99 | No | 3–7 business days |
| [TSH (Thyroid Stimulating Hormone)](https://www.test-well.com/tests/tsh) | Test | $26.99 | $32.99 | No | 1–3 business days |
| [Free T4 (Thyroxine)](https://www.test-well.com/tests/free-t4-test) | Test | $23.99 | $29.99 | No | 1–3 business days |
| [Hemoglobin A1c](https://www.test-well.com/tests/hemoglobin-a1c) | Test | $21.99 | $27.99 | No | 2–4 business days |
| [Glucose, Fasting](https://www.test-well.com/tests/glucose-fasting) | Test | $24.99 | $30.99 | Yes | 1–3 business days |
| [CBC with Differential](https://www.test-well.com/tests/cbc-with-differential) | Test | $21.99 | $27.99 | No | 1–3 business days |
| [Comprehensive Metabolic Panel](https://www.test-well.com/tests/comprehensive-metabolic-panel) | Test | $22.99 | $28.99 | Yes | 1–3 business days |
| [C-Reactive Protein (CRP)](https://www.test-well.com/tests/crp) | Test | $26.99 | $32.99 | No | 2–4 business days |
| [Celiac Disease Panel](https://www.test-well.com/tests/celiac-disease-comprehensive) | Test | $124.99 | $130.99 | No | 3–7 business days |

Prices are cash-pay; every order adds one $6.00 lab processing fee. Physician authorization included.

## Common questions

### Should I order tests or see a doctor first?

Both is reasonable: order the baseline so results are ready for the visit, but book the visit. Unexplained weight loss is a symptom clinicians want to evaluate directly.

## Related

- [What blood tests should you get for fatigue?](https://www.test-well.com/symptoms/fatigue)
- [Which blood tests help explain brain fog?](https://www.test-well.com/symptoms/brain-fog)
- [What blood tests should you get for hair loss?](https://www.test-well.com/symptoms/hair-loss)
- [What blood tests check for causes of unexplained weight gain?](https://www.test-well.com/symptoms/weight-gain)
- [All symptoms](https://www.test-well.com/symptoms)
- [Browse by condition](https://www.test-well.com/conditions)

---

Medically reviewed by Youmna DiStefano, MD (Medical Reviewer, TestWell); last reviewed 2026-09-06. Review policy: https://www.test-well.com/editorial-policy

Canonical page: https://www.test-well.com/symptoms/unexplained-weight-loss
Machine-readable catalog: https://www.test-well.com/api/catalog.json · MCP server: https://www.test-well.com/mcp · Overview for agents: https://www.test-well.com/llms.txt

Prices are cash-pay, in USD, and include physician authorization; every order adds one flat $6 lab processing fee. Educational content is not a diagnosis — discuss results with a clinician.