ASH Issues New Ferritin Thresholds for Iron Deficiency Diagnosis

The American Society of Hematology (ASH) published new evidence-based clinical practice guidelines recommending higher serum ferritin thresholds for diagnosing iron deficiency. The recommendations aim to support earlier and more accurate diagnosis, irrespective of whether anemia is present.¹,²

The guidelines address diagnosis across several populations, including adults, young children, menstruating or pregnant individuals, people with heavy menstrual bleeding, and individuals with inflammation or chronic health conditions. They aim to address variability in testing practices and diagnostic thresholds that can make iron deficiency difficult to recognize.

“These updated ferritin thresholds provide clear guidance in an area where consensus has been lacking,” said guideline chair Jacquelyn M. Powers, MD, MS, section chief of hematology at Texas Children’s Hospital and associate professor in the department of pediatrics at Baylor College of Medicine, in a statement. “We hope these recommendations empower patients to better understand and ask for the testing they need and that health systems adopt these thresholds for diagnosis.”²

What Is Ferritin?

Ferritin is a protein that stores iron, while serum ferritin is used as a marker of the body's iron stores. Iron is essential for producing hemoglobin, a molecule that carries oxygen throughout the body. When iron stores are too low, iron deficiency can develop and may progress to iron deficiency anemia if untreated.²

Importantly, the guidelines are intended to support the diagnosis of iron deficiency **irrespective of whether anemia is present.**¹

New Ferritin Thresholds for Iron Deficiency

ASH recommends the following serum ferritin thresholds for diagnosing iron deficiency:

• Children aged 9 months to 4 years: 20 ng/mL or lower
• Adults, menstruating or pregnant individuals: 30 ng/mL or lower
• High-risk groups: 50 ng/mL or lower, including individuals with heavy menstrual bleeding and pregnant individuals with anemia
• Adults with inflammation: serum ferritin under 100 ng/mL or transferrin saturation under 20%, including individuals with cancer, inflammatory bowel disease, or infectious disease¹,²

The multidisciplinary guideline panel developed 5 recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach and systematic evidence reviews of studies informing diagnostic thresholds across populations. The evidence reviews included studies available through July 2025.¹

How the New Thresholds May Change Diagnosis

Under the new guidance, the recommended ferritin cutoff numbers are higher across populations. As a result, some people who were previously not considered to have iron deficiency based on their ferritin levels may now meet the criteria, particularly if their levels were close to the previous cutoff.²

The guidelines also include remarks on considerations for other diagnostic thresholds and identify gaps in the available evidence and priorities for future research.¹

Symptoms and Clinical Impact

Iron deficiency can cause symptoms such as lack of energy, shortness of breath, rapid heartbeat, headache, and pale skin. If untreated, iron deficiency can progress to iron deficiency anemia. High-risk populations include pregnant or menstruating individuals, children, people with gastrointestinal conditions, individuals with dietary restrictions, those experiencing blood loss, and people with chronic health conditions.²

“Iron deficiency and iron deficiency anemia are among the most common yet neglected medical conditions globally,” said ASH President Robert S. Negrin, MD, in a statement. “Many patients live with symptoms such as fatigue, weakness, dizziness, or difficulty concentrating for months or even years before iron deficiency is recognized. These guidelines are an important step toward closing that gap by helping clinicians diagnose iron deficiency earlier and more accurately, so more patients can receive the care they need.”²

According to ASH, additional guidance on the treatment of iron deficiency is anticipated in 2027.²

References

1. Powers JM, Lim MY, Achebe MO, et al. American Society of Hematology 2026 guidelines for diagnosis of iron deficiency. Blood Adv. 2026. doi:10.1182/bloodadvances.2025015950

2. American Society of Hematology. ASH sets new standards for diagnosing iron deficiency. Medical XpressSeptember 16, 2026. Accessed September 16, 2026. https://medicalxpress.com/news/2026-09-ash-standards-iron-deficiency.html