Hemophagocytic lymphohistiocytosis

Affects many body systems. Also called: HLH.

How common is Hemophagocytic lymphohistiocytosis in the US?

Adult hospitalizations with a principal billing diagnosis of hemophagocytic lymphohistiocytosis (HLH), identified in the National Inpatient Sample: Seven hundred fifty (Adult hospitalizations with a principal diagnosis of HLH, United States, National Inpatient Sample, 2016-2017 (count over 2 years, not an annual rate); United States (National Inpatient Sample, nationally representative hospital sample), 2016-2017). Source: Journal of clinical rheumatology : practical reports on rheumatic & musculoskeletal diseases, 2022. Label: REPORTED.

• Seven hundred fifty Adult hospitalizations with a principal billing diagnosis of hemophagocytic lymphohistiocytosis (HLH), identified in the National Inpatient Sample. Out of: Adult hospitalizations with a principal diagnosis of HLH, United States, National Inpatient Sample, 2016-2017 (count over 2 years, not an annual rate). Where: United States (National Inpatient Sample, nationally representative hospital sample). When: 2016-2017. Adult hospitalizations with HLH as the principal diagnosis only; excludes pediatric HLH and cases where HLH was a secondary diagnosis. Label: REPORTED.

  Seven hundred fifty hospitalizations had a principal billing diagnosis of HLH.

  Source: Hemophagocytic Lymphohistiocytosis Hospitalizations in Adults and Its Association With Rheumatologic Diseases: Data From Nationwide Inpatient Sample. Journal of clinical rheumatology : practical reports on rheumatic & musculoskeletal diseases, 2022. PubMed 33337810. DOI 10.1097/RHU.0000000000001670.

Each figure measures something different. Do not compare them with each other or with other conditions.

Medical codes

• ICD-10-CM FY2026: D76.1 Hemophagocytic lymphohistiocytosis (exact). Inherited and acquired forms share this code.

Research activity

As of 2026-09-24: 122 registered studies on ClinicalTrials.gov (search Hemophagocytic Lymphohistiocytosis) and 2,509 PubMed records, 2021 to 2025. A count of records is not how common or serious the condition is.

Population information, not medical advice. Methodology · Known limitations