Symptom → lab tests
What blood tests check for causes of numbness and tingling?
Short answer
Tingling in the hands or feet has two very common testable causes: vitamin B12 deficiency and diabetes-related nerve damage. Vitamin B12, hemoglobin A1c and glucose come first, with a metabolic panel for kidney function and electrolytes, thyroid testing, and folate. Sudden or one-sided numbness is an emergency, not a lab question.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
When should you see a clinician instead of ordering a test?
- Sudden numbness on one side of the body, facial droop, trouble speaking or severe headache — call emergency services
- Numbness spreading upward, weakness, or loss of bladder or bowel control — seek care immediately
Why these tests for numbness and tingling?
B12 deficiency damages nerves and can do so before anemia appears; it is treatable and easy to miss. High blood sugar damages small nerve fibers over years — A1c is the screen. Low calcium or magnesium, kidney disease and hypothyroidism also cause tingling and show up on the CMP, magnesium and TSH.
Which conditions do these tests help evaluate?
- Diabetes & Blood Sugar — A1c, fasting glucose and insulin to screen for prediabetes and diabetes.
- Anemia — CBC, iron studies, ferritin, B12 and folate to find the cause of fatigue and low energy.
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 |
|---|---|---|---|---|
| Vitamin & Mineral Deficiency PanelSaves $106.92 vs ordering the tests separately | Panel · 9 tests | $189.99 | No | 3–5 business days |
| Diabetes Screening PanelSaves $9.98 vs ordering the tests separately | Panel · 3 tests | $59.99 | Yes | 2–5 business days |
| Vitamin B12 | Test | $25.99 | No | 2–4 business days |
| Hemoglobin A1c | Test | $21.99 | No | 2–4 business days |
| Glucose, Fasting | Test | $24.99 | Yes | 1–3 business days |
| Comprehensive Metabolic Panel | Test · 14 biomarkers | $22.99 | Yes | 1–3 business days |
| TSH (Thyroid Stimulating Hormone) | Test | $26.99 | No | 1–3 business days |
| Folate (Vitamin B9) | Test | $32.99 | No | 2–4 business days |
| Magnesium | Test | $19.99 | No | 2–4 business days |
Common questions
My B12 is borderline. Could it still cause tingling?
Yes. Neurological symptoms occur at low-normal B12 levels in some people; methylmalonic acid can clarify. Discuss borderline values with a clinician before supplementing.
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.