Why are my ferritin 8 ng/mL and hemoglobin 10.2 g/dL so low?

By Sina Hartung, MMSC-BMI, Harvard Medical SchoolReviewed by Eureka Health Medical Group
Published: July 4, 2025Updated: July 4, 2025

Summary

A ferritin of 8 ng/mL means your iron stores are almost empty, and a hemoglobin of 10.2 g/dL confirms mild-to-moderate anemia. Together they strongly suggest iron-deficiency anemia—usually from chronic blood loss, increased demand, or poor absorption. You need evaluation for the bleeding source, iron replacement, and follow-up labs within eight weeks.

Does a ferritin of 8 ng/mL and hemoglobin of 10.2 g/dL indicate iron-deficiency anemia?

Yes—those numbers match the laboratory definition of iron-deficiency anemia for most adults. Ferritin under 15 ng/mL signals that your body’s iron reserve is nearly gone, and hemoglobin below 12 g/dL in women or 13 g/dL in men is anemic.

  • Ferritin under 15 equals empty iron storesMore than 95 % of adults with ferritin below 15 ng/mL have exhausted iron reserves, according to WHO criteria.
  • Hemoglobin 10.2 shows moderate anemiaLaboratories call 10–12 g/dL moderate anemia; symptoms start for many people below 11 g/dL.
  • Iron deficiency is the commonest causeWorldwide, 50 % of anemias are due to iron lack, especially in menstruating women and people with intestinal bleeding.
  • Other causes still possibleAnemia of chronic disease, thalassemia, or kidney problems can overlap, so confirm with a full iron panel.
  • Ferritin below 15 ng/mL is highly specific for iron-deficiency anemiaClinical guidance notes that serum ferritin under 15 ng/mL has a diagnostic specificity exceeding 95 % for iron-deficiency anemia, making an 8 ng/mL result virtually diagnostic. (Elsevier)
  • Using a 30 ng/mL cutoff nearly triples detected casesIn a primary-care cohort, raising the ferritin threshold from 15 to 30 ng/mL increased iron-deficiency diagnoses from 10.9 to 29.9 per 1,000 patient-years, highlighting the impact of cutoff choice on case finding. (PMC)

References

When should low ferritin and anemia be treated as an emergency?

Anemia can strain the heart and hide serious bleeding. Seek urgent care if you develop the warning signs below.

  • Breathlessness or chest painShortness of breath at rest or chest tightness may signal cardiac stress from low oxygen.
  • Fast heartbeat over 120 bpmPersistent tachycardia suggests the body is compensating for low hemoglobin.
  • Black or bloody stoolsMelena or red blood in stool often means gastrointestinal bleeding that needs endoscopy.
  • Extreme fatigue or faintingSyncope, dizziness, or inability to walk across a room warrants same-day evaluation.
  • Ferritin below 30 µg/L signals true iron deficiencySerum ferritin under this cut-off is the most sensitive and specific marker of depleted iron stores and should prompt evaluation even before hemoglobin falls. (PMC)
  • Iron deficiency is especially prevalent in women and endurance athletesAbout 9–11 % of adult women are iron deficient versus roughly 1 % of men, and studies of high-school cross-country runners found low ferritin in 34 % of girls but only 8 % of boys at season start. (RW)

References

What daily steps can I take right now to raise my iron levels safely?

While you wait to see your clinician, diet and lifestyle changes can improve absorption and reduce losses.

  • Eat 18 mg of iron-rich foods dailyA 3-oz serving of beef liver gives 5 mg iron; add spinach, pumpkin seeds, or fortified cereal to reach the goal.
  • Pair iron with vitamin CDrinking 120 mL orange juice with beans can increase non-heme iron absorption by up to 50 %.
  • Avoid tea, coffee, and calcium with iron mealsPolyphenols and calcium cut iron uptake by 40–60 %; leave a two-hour gap.
  • Track menstrual lossesUsing a menstrual cup lets you measure flow; heavy bleeding above 80 mL per cycle often needs gynecologic care.
  • Confirm deficiency with a ferritin blood testA ferritin result below 12–15 ng/mL signals depleted iron stores and tells you whether diet alone is enough or if supplements are required. (Mito)
  • Stop iron pills and seek care if you develop sudden nausea or stomach painSymptoms such as nausea, vomiting, abdominal pain, dizziness or seizures after taking iron can indicate iron poisoning; discontinue the supplement and get emergency help. (LW)

References

Which lab tests confirm iron deficiency and rule out other causes?

Your doctor will likely order a full iron study and screen for hidden bleeding or inflammation.

  • Serum iron and transferrin saturationA saturation below 15 % supports iron deficiency; normal is 20–50 %.
  • Total iron-binding capacity (TIBC)TIBC rises above 400 µg/dL when the body is craving iron.
  • C-reactive protein (CRP) or ESRInflammation can falsely raise ferritin; a normal CRP makes low ferritin more reliable.
  • Stool occult blood or colonoscopyIn adults over 40, up to 30 % of new iron-deficiency cases stem from colorectal bleeding.
  • Ferritin below 30 ng/mL is highly specific for iron-deficiencyA markedly low ferritin has >98 % specificity for iron deficiency, making it the single best standalone test when inflammation is absent. (Medscape)
  • CBC typically shows microcytic, hypochromic red cells and elevated RDWIron-deficiency anemia usually presents with MCV < 80 fL, low MCH/MCHC, and RDW > 14.5 %, helping distinguish it from thalassemia traits. (NIH)

References

How are iron supplements and other treatments chosen and monitored?

Therapy depends on your tolerance, absorption, and the cause of iron loss.

  • Oral ferrous sulfate standard dose65 mg elemental iron once daily raises hemoglobin about 1 g/dL every two weeks in responsive patients.
  • Alternate-day dosing cuts side effectsTaking iron Monday-Wednesday-Friday improves absorption by 34 % and lowers nausea, per 2020 trials.
  • Intravenous iron for severe or malabsorptive casesIV iron can replace total body stores in one visit when hemoglobin is under 8 g/dL or oral therapy fails.
  • Treat the bleeding sourceFibroids, ulcers, or celiac disease must be fixed; otherwise anemia returns within months.
  • Follow-up iron studies in 4–8 weeks guide dose adjustmentsRepeat hemoglobin and ferritin 4–8 weeks after starting therapy; if values have not improved, modify dose or switch formulation, and continue supplementation for at least 3–6 months after normalization to fully replenish stores. (DrOracle)
  • Starting with 28–50 mg elemental iron daily reduces gastrointestinal side effectsClinical guidance suggests initiating oral therapy with 28–50 mg elemental iron per day, combined with dietary enhancers of absorption, to improve tolerance before escalating the dose or considering intravenous iron. (SMW)

References

What can Eureka’s AI doctor do if your ferritin is 8 and hemoglobin 10.2?

Eureka’s clinician-built AI chats through your symptoms and guides evidence-based next steps.

  • Recommends guideline-aligned testsThe AI suggests a CBC, iron panel, CRP, and stool occult blood, then routes the request to a licensed physician for approval.
  • Triages red-flag symptoms in real timeIf you report chest pain or black stools, Eureka advises emergency care and explains why.
  • Builds a food plan around iron absorptionYou receive a printable grocery list calibrated to 18–20 mg iron a day.

Why many patients with iron deficiency use Eureka’s AI doctor alongside their physician

People with chronic anemia often need ongoing tracking and quick answers between office visits.

  • High patient satisfactionWomen using Eureka for anemia management rate the app 4.8 / 5 stars for helpfulness.
  • Automatic lab trend graphsUpload PDFs of your blood work and Eureka plots hemoglobin and ferritin over time so you see progress.
  • Visit-prep summariesBefore appointments, the AI drafts questions and a symptom timeline you can email to your clinician.

Become your own doctor

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Frequently Asked Questions

Is a ferritin of 8 dangerous?

It means your iron reserve is almost gone; while not life-threatening by itself, it needs treatment to prevent severe anemia.

Can low ferritin cause hair loss?

Yes—ferritin below 30 ng/mL has been linked to increased hair shedding, especially in women.

How long does it take for iron pills to work?

Most people see hemoglobin rise within two weeks; full correction of ferritin can take three months or more.

Should I take iron with food or on an empty stomach?

Empty stomach maximizes absorption but often causes nausea; if you feel sick, take it with a small snack rich in vitamin C.

Can I exercise while anemic?

Light activity is fine if you are not dizzy or breathless, but avoid high-intensity workouts until hemoglobin is above 11 g/dL.

Do vitamin B12 or folate matter here?

They can also cause anemia; if your levels are borderline, your doctor may supplement them alongside iron.

Why does my doctor want a colonoscopy?

In adults over 40, hidden bleeding from polyps or cancer is a common cause of iron-deficiency anemia and must be ruled out.

Is IV iron safe?

Modern IV formulations have a serious reaction rate below 1 %; they are monitored in a clinic for at least 30 minutes after infusion.

This content is for informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare provider for diagnosis, treatment, and personalized medical recommendations.

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