What does a ferritin level of 155 indicate?

Ferritin 155 μg/L: Clinical Interpretation

A ferritin level of 155 μg/L is within the normal range for adult men and elevated for adult women, indicating adequate iron stores in the absence of inflammation. This value essentially rules out iron deficiency but requires clinical context to determine if it represents normal iron status, inflammation, or early iron overload 1.

Normal Reference Ranges

• Adult men: Average serum ferritin is 135 μg/L (normal range 20-200 μg/L), making 155 μg/L completely normal 1
• Adult women: Average serum ferritin is 43 μg/L (normal range 15-150 μg/L), making 155 μg/L mildly elevated 1
• Children aged 6-24 months: Average is approximately 30 μg/L 1

Clinical Significance of This Value

Iron deficiency is effectively excluded at this ferritin level:

• Values >150 μg/L rarely occur with absolute iron deficiency, even in the presence of inflammation 1
• Normal serum ferritin concentrations essentially rule out iron overload in hemochromatosis, as ferritin is a highly sensitive test for iron stores 2
• The relationship is direct: 1 μg/L of serum ferritin equals approximately 10 mg of stored iron, suggesting this patient has roughly 1,550 mg of stored iron 1

Critical Interpretation Algorithm

Step 1: Assess for inflammation or acute illness

• Ferritin is an acute-phase protein that rises independently of iron status during infections, inflammation, or tissue damage 1, 2
• Common causes of elevated ferritin unrelated to iron include: chronic liver disease (alcoholic, hepatitis B/C, NAFLD), malignancy, chronic inflammatory conditions 2
• In hospitalized adults with ferritin >2,000 ng/mL, hepatocellular injury was the most common diagnosis (126/333 patients), followed by infection (96/333) 3

Step 2: Check transferrin saturation (TS) to complete iron assessment

• If TS <20% with ferritin 155 μg/L: This suggests anemia of chronic disease (inflammatory iron sequestration) rather than true iron deficiency 2
• If TS ≥45% with ferritin 155 μg/L: Consider early hemochromatosis screening with HFE genotyping, particularly in males with family history 2
• Neither serum ferritin nor TS alone provides a complete picture—they must be interpreted together 1

Step 3: Consider patient demographics

• For adult men: 155 μg/L is entirely normal and requires no further action unless TS is abnormal 1
• For premenopausal women: This represents mild elevation above the average of 43 μg/L; check inflammatory markers (CRP/ESR) to determine if this reflects inflammation rather than increased iron stores 1, 4
• For obese patients: Ferritin correlates strongly with BMI and CRP (r = 0.86 and 0.87 respectively), functioning more as an inflammation marker than iron status indicator 4

Hemochromatosis Screening Context

• In C282Y homozygotes, serum ferritin was elevated (>300 μg/L in men, >200 μg/L in women) in 88% of males and 57% of females 2
• Ferritin <1,000 μg/L accurately predicts absence of cirrhosis in hemochromatosis patients, independent of disease 2
• If TS ≥45% or ferritin above upper limit of normal, HFE mutation analysis should be performed 2

Common Pitfalls to Avoid

• Do not interpret ferritin in isolation: Always obtain TS to distinguish between adequate iron stores, functional iron deficiency, and anemia of chronic disease 1
• Do not assume iron overload: A ferritin of 155 μg/L is far below the threshold (>1,000 μg/L) associated with significant iron overload complications 2
• In overweight/obese patients: Ferritin may be falsely elevated due to inflammation; complete iron profile including transferrin is necessary for accurate assessment 4
• Diurnal variation: Serum iron shows time-of-day variation, so ensure consistent collection timing if serial measurements are needed 1

Recommended Next Steps

• If male with no symptoms: No further evaluation needed; this is normal 1
• If female or symptomatic: Measure TS and inflammatory markers (CRP/ESR) to determine if elevation is inflammation-related 1, 4
• If TS ≥45%: Proceed with HFE genotyping to screen for hereditary hemochromatosis 2
• If TS <20% despite ferritin 155 μg/L: Investigate for anemia of chronic disease and underlying inflammatory conditions 2, 1