U.S. flag

An official website of the United States government


Send to:

Choose Destination

Hemophilia b(m)

MedGen UID:
Concept ID:
Disease or Syndrome


The major types of this condition are hemophilia A (also known as classic hemophilia or factor VIII deficiency) and hemophilia B (also known as Christmas disease or factor IX deficiency). Although the two types have very similar signs and symptoms, they are caused by variants (also known as mutations) in different genes. People with an unusual form of hemophilia B, known as hemophilia B Leyden, experience episodes of excessive bleeding in childhood but have few bleeding problems after puberty.

Hemophilia is a bleeding disorder that slows the blood clotting process. People with this condition experience prolonged bleeding or oozing following an injury, surgery, or having a tooth pulled. In severe cases of hemophilia, continuous bleeding occurs after minor trauma or even when there is no obvious injury (sometimes called spontaneous bleeding). Serious complications can result from bleeding into the joints, muscles, brain, or other internal organs. Milder forms of hemophilia do not necessarily involve spontaneous bleeding, and the condition may not become apparent until abnormal bleeding occurs following surgery or a serious injury. [from MedlinePlus Genetics]

Professional guidelines


Moonla C, Sosothikul D, Pongtanakul B, Suwanawiboon B, Traivaree C, Natesirinilkul R, Sirachainan N, Angchaisuksiri P
Orphanet J Rare Dis 2023 May 10;18(1):110. doi: 10.1186/s13023-023-02718-1. PMID: 37161533Free PMC Article
Franchini M, Mannucci PM
Semin Thromb Hemost 2022 Nov;48(8):904-910. Epub 2022 Sep 15 doi: 10.1055/s-0042-1756188. PMID: 36108649
Meeks SL, Batsuli G
Hematology Am Soc Hematol Educ Program 2016 Dec 2;2016(1):657-662. doi: 10.1182/asheducation-2016.1.657. PMID: 27913543Free PMC Article

Supplemental Content

Table of contents

    Clinical resources

    Practice guidelines

    • PubMed
      See practice and clinical guidelines in PubMed. The search results may include broader topics and may not capture all published guidelines. See the FAQ for details.
    • Bookshelf
      See practice and clinical guidelines in NCBI Bookshelf. The search results may include broader topics and may not capture all published guidelines. See the FAQ for details.

    Recent activity

    Your browsing activity is empty.

    Activity recording is turned off.

    Turn recording back on

    See more...