Symptom → lab tests
Which blood tests should you get for heavy periods?
Short answer
Heavy periods do two things labs can see: they drain iron, and they can signal a hormone or clotting cause. A CBC and ferritin check for iron deficiency and anemia; TSH screens the thyroid; prolactin, LH/FSH and estradiol look at ovulation; and a clotting screen (PT/INR, PTT) plus von Willebrand testing is considered when bleeding has been heavy since the first period or comes with easy bruising. Structural causes need an ultrasound, not a lab.
Medically reviewed by Youmna DiStefano, MD · Last reviewed September 2026
When should you see a clinician instead of ordering a test?
- Soaking through a pad or tampon every hour for several hours, or passing clots larger than a quarter — same-day care
- Dizziness, fainting, racing heart or shortness of breath with heavy bleeding
- Bleeding after menopause, or bleeding between periods that is new
- Heavy bleeding with a positive pregnancy test
Why these tests for heavy periods?
Iron loss is the most common consequence of heavy bleeding and the one most often missed: ferritin can be low with a normal hemoglobin, causing fatigue and hair shedding long before anemia appears. A CBC adds hemoglobin and platelets.
Thyroid disorders, high prolactin and PCOS all disrupt ovulation and produce heavy or prolonged bleeding; TSH, prolactin, LH/FSH and estradiol are the usual set. hCG is checked whenever pregnancy is possible.
Inherited bleeding disorders — von Willebrand disease is found in roughly one in eight women with heavy periods referred for evaluation — are screened with PT/INR and PTT and confirmed with specific factor testing through a clinician.
Which conditions do these tests help evaluate?
- Anemia — CBC, iron studies, ferritin, B12 and folate to find the cause of fatigue and low energy.
- Thyroid Problems — TSH, Free T4/T3 and antibodies to evaluate an under- or over-active thyroid.
- PCOS — Androgens, LH/FSH, insulin and thyroid markers to investigate PCOS.
- Perimenopause — Estradiol, FSH, LH and thyroid to make sense of changing cycles and symptoms.
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 |
|---|---|---|---|---|
| Baseline Anemia PanelSaves $56.96 vs ordering the tests separately | Panel · 5 tests | $74.99 | Yes | 2–4 business days |
| Women's Hormone PanelSaves $129.90 vs ordering the tests separately | Panel · 11 tests | $239.99 | No | 3–5 business days |
| Blood Clotting PanelSaves $50.97 vs ordering the tests separately | Panel · 4 tests | $149.99 | No | 3–7 business days |
| CBC with Differential | Test · 14 biomarkers | $21.99 | No | 1–3 business days |
| Ferritin | Test | $24.99 | No | 1–3 business days |
| Iron Panel (Iron, TIBC & Ferritin) | Test · 4 biomarkers | $32.99 | Yes | 2–5 business days |
| TSH (Thyroid Stimulating Hormone) | Test | $26.99 | No | 1–3 business days |
| Prolactin | Test | $39.99 | No | 2–4 business days |
| FSH (Follicle Stimulating Hormone) | Test | $29.99 | No | 2–4 business days |
| LH (Luteinizing Hormone) | Test | $36.99 | No | 1–3 business days |
| Estradiol (E2) | Test | $35.99 | No | 1–3 business days |
| PT and PTT (Prothrombin & Partial Thromboplastin Time) | Test · 3 biomarkers | $54.99 | No | 1–3 business days |
| Pregnancy Test (Quantitative hCG) | Test | $26.99 | No | 1–3 business days |
Common questions
Can heavy periods cause low iron without anemia?
Yes — ferritin falls first. Many women with heavy periods have a normal hemoglobin and a ferritin under 30 ng/mL, which is enough to cause fatigue, hair loss and poor exercise tolerance.
Should I be tested for a bleeding disorder?
If periods have been heavy since they started, or you also bruise easily, bleed long after cuts or dental work, or a relative has a bleeding disorder — yes. Ask about von Willebrand testing; it is under-diagnosed.
Do blood tests show fibroids?
No. Fibroids, polyps and adenomyosis are structural and need a pelvic ultrasound. Labs measure the consequences (iron) and the hormonal contributors.
Educational content, not a diagnosis. Lab results are one input; a clinician interprets them with your history and exam.