Health Library
Hemophilia in Children

What is Hemophilia?

Hemophilia is a rare, life-long disorder in which the blood doesn’t clot properly. Children with hemophilia may bleed longer after an injury than children who don’t have hemophilia. Bleeding can happen internally, into joints or muscles. Bleeding can also happen externally from cuts or injuries.

Most people who have hemophilia are male. Hemophilia can also affect women too, but it is rarer. The disease tends to run in families. But children without a family history of hemophilia can get it, too. Hemophilia affects people from all racial and ethnic groups.

There is currently no cure for hemophilia. Excellent medical care is critical for children with hemophilia to have the best health possible.

Hemophilia Causes

Proteins in the blood called “clotting factors” help with clotting. People with hemophilia have low levels of clotting factors VIII (8) or IX (9). The lower the amount of clotting factor (often called “factor”), the more likely a person is to have problems with bleeding. There are two kinds of hemophilia:

  • Hemophilia A. Children who are low in or do not have clotting factor VIII have hemophilia A. This condition occurs in about 1 in 5,000 live male births.
  • Hemophilia B. Children who are low in or do not have clotting factor IX have hemophilia B. This condition is less common, occurring in about 1 in 20,000 to 25,000 live male births.

How Is Hemophilia Inherited?

A gene mutation (change) on the X chromosome causes hemophilia. This prevents the body from making enough clotting factor VIII or IX.

  • About 70% of boys with hemophilia have another family member with hemophilia.
  • 30% of boys with hemophilia do not have a family history of hemophilia.

Girls can have these gene changes, too. This is less common. About 10% of those girls have hemophilia. The other 90% are carriers of hemophilia because they can pass it to their future children.

Hemophilia and Bleeding Problems

To understand how hemophilia affects the blood, we can first look at how clotting happens in a person without hemophilia.

When a person who doesn’t have hemophilia is injured, the blood vessels around the injured area get smaller to let less blood through. Small blood particles (platelets) stick to the injured blood vessels and form a sticky plug. At the same time, clotting factors in the blood make fibrin. Fibrin are strands of protein that weave together through the platelet plug. This creates a “fibrin clot.”

Children with hemophilia don’t have enough of clotting factor VIII or IX to make a good fibrin clot. The clot they form is weak and bleeding continues.

Hemophilia Types

Hemophilia can be mild, moderate or severe. These levels depend on how much clotting factor is in a person’s blood.

Mild Hemophilia Moderate Hemophilia Severe Hemophilia
Factor levels are 5-40% Factor levels are 1 –5% Factor levels are less than 1%
Possible reasons that bleeding starts:
  • Injury
  • Surgery
  • Dental Work
Possible reasons that bleeding starts:
  • Injury
  • Surgery
  • Dental Work
  • Spontaneous (no injury)
Possible reasons that bleeding starts:
  • Spontaneous (no injury)
  • Injury
  • Surgery
  • Dental Work
Chance of spontaneous bleeding is rare. Chance of spontaneous bleeding can happen. Chance of spontaneous bleeding is common.

Hemophilia Symptoms

The symptoms of hemophilia include:

  • Easy bruising
  • Bleeding after minor injuries
  • Joint swelling or pain
  • Soft tissue swelling
  • Swollen and painful muscles
  • Bleeding from surgery or a procedure
  • Nosebleeds

Some children with hemophilia experience internal bleeding, especially in the area around their joints. This bleeding isn’t visible. It can be serious. Signs of a bleed inside the joint include:

  • Pain
  • Tingling
  • Warmth

Hemophilia Diagnosis

If you or your child’s doctor is concerned that your child may have hemophilia, the doctor can order blood tests to:

  • Measure the levels of clotting factor VIII or IX in your child’s blood
  • See whether your child has the genetic mutation (change) that causes hemophilia

If your child tests positive for the genetic mutation that causes hemophilia, you may want to consider having other members of your family tested, too.

Children with severe hemophilia usually are diagnosed before they turn 1 year old. People with mild forms of the disease might not know they have hemophilia until later in life when they notice a bleeding problem. For instance, some people discover they have hemophilia only after they bleed excessively during a dental or surgical procedure.

Hemophilia Treatment

The purpose of treatment is to prevent bleeding before it starts, stop bleeding after it begins, and lower a child’s risk of bleeding complications. Children with hemophilia should see their comprehensive care team every six to 12 months for follow-up care. Patients with special issues, such as frequent joint bleeds, may need to come to the clinic more often.

Treatment for hemophilia can include:

  • Factor replacement therapy (for hemophilia A and B)
  • Antifibrinolytics (for hemophilia A and B)
  • Bispecific antibody therapy (hemophilia A only)
  • Desmopressin (DDAVP) (hemophilia A only)

Talk to the care team about which over-the-counter drugs your child can have. If you are treating pain symptoms or a fever, it’s important to avoid non-steroidal anti-inflammatory drugs (such as Advil, Motrin, ibuprofen, naproxen, or aspirin). These drugs can increase bleeding problems in children with hemophilia.

Factor Replacement Therapy

Factor replacement therapy is one of the main treatments for hemophilia. It involves replacing a person’s missing clotting factor so that the blood can clot properly. Factor replacement therapy can stop bleeding episodes that are already happening. It can prevent most bleeding episodes when given regularly.

Your child can receive factor replacement therapy through a vein in the arm or a port in their chest. Children who need regular treatment can learn how to give themselves factor replacement therapy at home

Replacement factor can be made from:

  • Recombinant factor. This type of factor is made in a laboratory. It is not made from human blood. Unlike factor made from human plasma, it carries no risk of infection.
  • Plasma from healthy blood donors. Factor made from plasma is tested for safety. It could cause infection. Using factor made from plasma could lessen a child’s risk of forming inhibitors. Inhibitors are proteins that prevent factor from working correctly.


Antifibrinolytics (like tranexamic acid and Amicar®) are drugs that stop clots from breaking down too fast. They do not help the body form a new clot. Antifibrinolytics are available in liquid or pill form. They can be given through an intravenous (IV) line. They treat nosebleeds and bleeding in the mouth. This includes bleeding that can happen after a dental procedure.

Bispecific Antibody Therapy

Bispecific antibody therapy helps the blood to clot. The name of this therapy is emicizumab or Hemlibra®. This medication is injected under the skin into fatty tissue on a regular schedule. It is usually given every week, every two weeks or every four weeks.

Monoclonal antibody therapy acts like factor VIII, but is not factor. It doesn’t treat active bleeds. It can help prevent bleeds in children who have moderate or severe hemophilia A. This medicine can be used in children who have inhibitors and those who don’t.

Desmopressin (DDAVP)

Desmopressin, also known as DDAVP, is a medication for some children with mild hemophilia A. It is used to stop bleeding. It can be given into the vein or inhaled through the nose in a spray form. Not all children with mild hemophilia A will respond to this medication.

“Prophylactic” vs. “On-Demand” Treatment for Hemophilia

Children with hemophilia may need “prophylactic” treatment to prevent bleeding, or “on-demand” treatment for active bleeds.

Prophylactic Treatment

Children with severe or moderately severe hemophilia need prophylactic (preventative) treatment to help prevent spontaneous bleeding. Those on prophylactic treatment can treat with factor replacement therapy or the bispecific antibody therapy. The care team will teach you and your child how to give this treatment at home. Prophylactic treatment can help reduce hospital time. It can decrease future joint damage.

On-Demand Treatment

Children who are having an active bleeding episode need “on-demand treatment” with factor. This type of therapy is for children who have mild or moderate hemophilia. It often happens in the hospital or clinic setting.

If you think that your child has a bleed, they should get treatment as soon as possible.

Having treatment quickly will:

  • Lessen pain
  • Prevent long-term damage
  • Decrease the number of treatments needed for the bleed or injury


About one in five people with hemophilia A and three in 100 people develop an antibody that stops the replacement factor from working. This antibody is called an inhibitor. It makes treating bleeds more difficult. Standard treatments don’t work. So the care team has to use different strategies to treat bleeds.

Hemophilia Prognosis

With excellent treatment and a healthy lifestyle, people with hemophilia can live fulfilling, active lives. Children with hemophilia need ongoing medical care from a multidisciplinary team of specialists to manage their symptoms and treat problems early.

The United States has about 140 Hemophilia Treatment Centers (HTCs) that bring together experienced teams of doctors, nurses and other health providers. Cincinnati Children’s has been designated as an HTC since 1975. Research shows that people with hemophilia who receive care at an HTC experience better health outcomes, including fewer hospital stays.

Last Updated 03/2023

Reviewed By Lisa Littner, Program Manager, CBDI

Who Treats This

Who treats this?

The Hemophilia and Bleeding Disorders Program at Cincinnati Children’s provides comprehensive, multidisciplinary care for children and young adults with mild, moderate and severe conditions.

Learn More