Symptom → lab tests
What blood tests are used for swollen ankles and legs?
Short answer
Swelling in both legs is checked for the organ causes — kidney (creatinine, eGFR, urine protein), liver (albumin, liver enzymes), heart (NT-proBNP) and thyroid (TSH) — with a comprehensive metabolic panel, urinalysis, NT-proBNP and TSH. Swelling in one leg, especially with pain or warmth, is a possible blood clot and needs same-day care.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
When should you see a clinician instead of ordering a test?
- Swelling in one leg with pain, warmth or redness — same-day care (possible clot)
- Leg swelling with shortness of breath, chest pain or inability to lie flat — emergency care
- Swelling with reduced urine output or foamy urine — see a clinician promptly
Why these tests for swollen ankles and legs?
Fluid leaks into tissue when the heart pumps weakly, when the kidneys lose protein, when the liver makes too little albumin, or when the thyroid is very underactive. The CMP covers kidney function and albumin, urinalysis finds protein loss, NT-proBNP screens for heart failure and TSH for hypothyroidism. Medications such as calcium-channel blockers and NSAIDs commonly cause ankle swelling too.
Which conditions do these tests help evaluate?
- Heart Disease Risk — Lipid panel, ApoB, Lp(a) and hs-CRP for a fuller cardiovascular risk picture.
- Fatty Liver — Liver enzymes, metabolic and lipid markers to assess fatty liver risk.
Which tests, and what do they cost?
Prices are cash-pay; every order adds one $6 lab processing fee. Physician authorization is included; no insurance or referral needed.
| Test or panel | Type | Price | Fasting | Results |
|---|---|---|---|---|
| Kidney Health PanelSaves $36.97 vs ordering the tests separately | Panel · 4 tests | $64.99 | Yes | 2–4 business days |
| Heart Health PanelSaves $47.96 vs ordering the tests separately | Panel · 5 tests | $99.99 | Yes | 3–5 business days |
| Comprehensive Metabolic Panel | Test · 14 biomarkers | $22.99 | Yes | 1–3 business days |
| Urinalysis, Complete | Test · 10 biomarkers | $17.99 | No | 1–3 business days |
| NT-proBNP (Heart Failure Marker) | Test | $224.99 | No | 1–3 business days |
| TSH (Thyroid Stimulating Hormone) | Test | $26.99 | No | 1–3 business days |
| CBC with Differential | Test · 14 biomarkers | $21.99 | No | 1–3 business days |
Common questions
Can a blood test rule out a blood clot?
A D-dimer can help exclude one in low-risk situations, but suspected clots need same-day clinical evaluation with ultrasound — order tests afterward, not instead.
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.