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What You Need to Know About Mild Hemophilia

Learn why experts consider the term to be a misnomer.
Author: By Donna Behen

Look up the word “mild” in the dictionary, and you’ll see it defined as “not severe, serious, or harsh.” But when it comes to mild hemophilia, experts say this classification of the disease is mild in name only.

“Just because your hemophilia is classified as mild, that doesn’t mean you are not at risk for serious bleeding problems,” says Stacy Croteau, M.D., MMS, medical director of the Boston Hemophilia Center.

Shannon Carpenter, M.D., M.S., associate director of the Hemophilia Treatment Center at Children’s Mercy in Kansas City, Missouri, agrees. “Mild hemophilia is a significant disorder requiring care and attention from a specialized medical team who understands the needs of this patient group,” she says.

What Is Mild Hemophilia?

Hemophilia is classified as either mild, moderate, or severe, depending on the person’s clotting factor levels. A diagnosis of mild hemophilia means your clotting factor levels are between 5% and 40% of normal; however, some clinicians use under 50% of normal as the cutoff. People with moderate hemophilia have clotting factor levels ranging from 1% to 5% of normal, and those with severe hemophilia have clotting factors levels that are less than 1% of normal.

In general, people with mild hemophilia experience prolonged bleeding only after serious injury, trauma, or surgery such as tooth extractions.

Women, girls, and people with the potential to menstruate (WGPPM) who have mild hemophilia often experience heavy menstrual bleeding. They are also at risk for hemorrhaging, or extensive bleeding, after childbirth.

READ MORE: Managing Mild Hemophilia: Be Prepared for the Unexpected

Mild Hemophilia Requires Treatment

“I think the biggest misconception is that people with mild hemophilia don’t have problems with bleeding, and so they may not seek treatment from a hemophilia treatment center,” Carpenter says. “But injuries can cause significant bleeding that the person may not recognize as easily and that may not trigger an adequate response from the health care team.”

Croteau notes that in many cases, mild hemophilia may have such little impact on someone’s day-to-day life that it’s easy for them to forget they even have a bleeding disorder. “When they do have a bleed or a muscle injury, they may not seek treatment as quickly as someone who has moderate or severe hemophilia,” she says. “It’s important to listen to your body.”

As people age and their risk of other health conditions such as cardiovascular disease grows, having mild hemophilia can present new challenges. “The management of other age-related health issues such as high blood pressure or heart disease may be more nuanced because of mild hemophilia, so it’s important a hematologist is involved in the treatment decision-making process,” Croteau says.

DIVE DEEPER: Mild Hemophilia: Symptoms Don’t Often Surface Until Major Surgery or Trauma

Mild Hemophilia May Not Always Stay Mild

In some cases, a person with mild hemophilia may develop an inhibitor, which is an antibody the immune system creates in response to the infusion of clotting factor concentrates.

When this happens, the person’s hemophilia classification can change from mild to severe. “This can be hard to adapt to, depending on the person’s stage of life at the time,” Carpenter says.

Heavy Periods Are an Often Overlooked Sign of Mild Hemophilia

Heavy menstrual bleeding is a common issue for WGPPM, and up to 20% of them attribute this to an underlying bleeding disorder. While most people who have heavy periods do not have a bleeding disorder, Croteau says it’s important to screen for hemophilia and other bleeding disorders early to identify WGPPM with mild hemophilia before they encounter other situations that could pose serious risks.

“For instance, if someone with undiagnosed mild hemophilia has their wisdom teeth removed, that procedure can result in serious bleeding problems,” Croteau says. “But if it’s identified sooner, that person can have proper treatment before surgery and avoid having bleeding complications.”