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The best way to treat hemophilia is to replace the missing blood clotting factor so that the blood can clot properly. This is mostly done by injecting treatment products, called clotting factor concentrates, into a person’s vein.

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The best way to treat hemophilia is to replace the missing blood clotting factor so that the blood can clot properly. This is mostly done by injecting treatment products, called clotting factor concentrates, into a person’s vein.

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Centers for Disease Control and Prevention

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Learn about treatments for hemophilia and hemophilia treatment centers (HTCs).

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Signs and symptoms of hemophilia include:Unexplained and excessive bleeding from cuts or injuries, or after surgery or dental work ,Many large or deep bruises ,Unusual bleeding after vaccinations ,Pain, swelling or tightness in your joints ,Blood in your urine or stool ,Nosebleeds without a known cause ,In infants, unexplained irritability.

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Signs and symptoms of hemophilia include:Unexplained and excessive bleeding from cuts or injuries, or after surgery or dental work ,Many large or deep bruises ,Unusual bleeding after vaccinations ,Pain, swelling or tightness in your joints ,Blood in your urine or stool ,Nosebleeds without a known cause ,In infants, unexplained irritability.

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Overview

Hemophilia is a rare disorder in which the blood doesn't clot in the typical way because it doesn't have enough blood-clotting proteins (clotting factors). If you have hemophilia, you might bleed for a longer time after an injury than you would if your blood clotted properly.

Small cuts usually aren't much of a problem. If you have a severe form of the condition, the main concern is bleeding inside your body, especially in your knees, ankles and elbows. Internal bleeding can damage your organs and tissues and be life-threatening.

Hemophilia is almost always a genetic disorder. Treatment includes regular replacement of the specific clotting factor that is reduced. Newer therapies that don't contain clotting factors also are being used.

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Symptoms

Signs and symptoms of hemophilia vary, depending on your level of clotting factors. If your clotting-factor level is mildly reduced, you might bleed only after surgery or trauma. If your deficiency is severe, you can bleed easily for seemingly no reason.

Signs and symptoms of spontaneous bleeding include:

Unexplained and excessive bleeding from cuts or injuries, or after surgery or dental work

Many large or deep bruises

Unusual bleeding after vaccinations

Pain, swelling or tightness in your joints

Blood in your urine or stool

Nosebleeds without a known cause

In infants, unexplained irritability

Bleeding into the brain

A simple bump on the head can cause bleeding into the brain for some people who have severe hemophilia. This rarely happens, but it's one of the most serious complications that can occur. Signs and symptoms include:

Painful, prolonged headache

Repeated vomiting

Sleepiness or lethargy

Double vision

Sudden weakness or clumsiness

Convulsions or seizures

When to see a doctor

Seek emergency care if you or your child has:

Signs or symptoms of bleeding into the brain

An injury in which the bleeding won't stop

Swollen joints that are hot to the touch and painful to bend

Causes

When a person bleeds, the body typically pools blood cells together to form a clot to stop the bleeding. Clotting factors are proteins in the blood that work with cells known as platelets to form clots. Hemophilia occurs when a clotting factor is missing or levels of the clotting factor are low.

Congenital hemophilia

Hemophilia is usually inherited, meaning a person is born with the disorder (congenital). Congenital hemophilia is classified by the type of clotting factor that's low.

The most common type is hemophilia A, associated with a low level of factor 8 The next most common type is hemophilia B, associated with a low level of factor 9.

Acquired hemophilia

Some people develop hemophilia with no family history of the disorder. This is called acquired hemophilia.

Acquired hemophilia is a variety of the condition that occurs when a person's immune system attacks clotting factor 8 or 9 in the blood. It can be associated with:

Pregnancy

Autoimmune conditions

Cancer

Multiple sclerosis

Drug reactions

Hemophilia inheritance

In the most common types of hemophilia, the faulty gene is located on the X chromosome. Everyone has two sex chromosomes, one from each parent. Females inherit an X chromosome from the mother and an X chromosome from the father. Males inherit an X chromosome from the mother and a Y chromosome from the father.

This means that hemophilia almost always occurs in boys and is passed from mother to son through one of the mother's genes. Most women with the defective gene are carriers who have no signs or symptoms of hemophilia. But some carriers can have bleeding symptoms if their clotting factors are moderately decreased.

Risk factors

The biggest risk factor for hemophilia is to have family members who also have the disorder. Males are much more likely to have hemophilia than are females.

Complications

Complications of hemophilia can include:

Deep internal bleeding. Bleeding that occurs in deep muscle can cause the limbs to swell. The swelling can press on nerves and lead to numbness or pain. Depending on where the bleeding occurs, it could be life-threatening.

Bleeding into the throat or neck. This can affect a person's ability to breathe.

Damage to joints. Internal bleeding can put pressure on the joints, causing severe pain. Left untreated, frequent internal bleeding can cause arthritis or destruction of the joint.

Infection. If the clotting factors used to treat hemophilia come from human blood, there's an increased risk of viral infections such as hepatitis C. Because of donor screening techniques, the risk is low.

Adverse reaction to clotting factor treatment. In some people with severe hemophilia, the immune system has a negative reaction to the clotting factors used to treat bleeding. When this happens, the immune system develops proteins that keep the clotting factors from working, making treatment less effective.

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Hemophilia is a rare disorder in which the blood doesn't clot in the typical way because it doesn't have enough blood-clotting proteins (clotting factors). If you have hemophilia, you might bleed for a longer time after an injury than you would if your blood clotted properly. Small cuts usually aren't much of a problem.

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According to the US Centers for Disease Control and Prevention , hemophilia occurs in approximately 1 in 5,617 live male births. There are between 30,000 – 33,000 males with hemophilia in the United States.  More than half of the people diagnosed with hemophilia A have the severe form.

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According to the US Centers for Disease Control and Prevention , hemophilia occurs in approximately 1 in 5,617 live male births. There are between 30,000 – 33,000 males with hemophilia in the United States.  More than half of the people diagnosed with hemophilia A have the severe form.

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What Is Hemophilia A?

Hemophilia A, also called factor VIII (8) deficiency or classic hemophilia, is a genetic disorder caused by missing or defective factor VIII (FVIII), a clotting protein. Although it is passed down from parents to children, about 1/3 of cases found have no previous family history.

According to the US Centers for Disease Control and Prevention (CDC), hemophilia occurs in approximately 1 in 5,617 live male births. There are between 30,000 - 33,000 males with hemophilia in the US*. More than half of people diagnosed with hemophilia A have the severe form. Hemophilia A is four times as common as hemophilia B. Hemophilia affects all races and ethnic groups.

Learn more about how blood clots at NHF's Steps for Living..

The Genetics of Hemophilia

A baseline understanding of hemophilia genetics is important for those individuals who have reason to suspect that a genetic predisposition for hemophilia exists in their family.
How is Hemophilia Inherited?
Hemophilia is passed down from parents to children.
Is Hemophilia Sex linked?
Yes, hemophilia is a sex linked disorder. The X and Y sex chromosomes help determine hemophilia inheritance patterns. The gene for hemophilia is carried on the X chromosome.
Is Hemophilia Dominant or Recessive?
Hemophilia is inherited in an X-linked recessive manner. Females inherit two X chromosomes, one from their mother and one from their father (XX). Males inherit an X chromosome from their mother and a Y chromosome from their father (XY). That means if a son inherits an X chromosome carrying hemophilia from his mother, he will have hemophilia. It also means that fathers cannot pass hemophilia on to their sons.

But because daughters have two X chromosomes, even if they inherit the hemophilia gene from their mother, most likely they will inherit a healthy X chromosome from their father and not have hemophilia. A daughter who inherits an X chromosome that contains the gene for hemophilia is called a carrier. She can pass the gene on to her children. Many women who carry the hemophilia gene also have low factor expression, which can result in heavy menstrual bleeding, easy bruising, and joint bleeds. Some women who have the hemophilia gene have factor expression low enough to be diagnosed with hemophilia.

For a female carrier, there are four possible outcomes for each pregnancy:
1. A girl who is not a carrier
2. A girl who is a carrier
3. A boy without hemophilia
4. A boy with hemophilia

Severity

(percentage breakdown of overall hemophilia population by severity)

* Severe (factor levels less than 1%) represent approximately 60% of cases
* Moderate (factor levels of 1-5%) represent approximately 15% of cases
* Mild (factor levels of 6%-30%) represent approximately 25% of cases

What are the Symptoms of Hemophilia A?

People with hemophilia A bleed longer than other people. Bleeds can occur internally, into joints and muscles, or externally, from minor cuts, dental procedures, or injuries. How often a person bleeds and the severity of those bleeds depends on how much FVIII a person produces naturally.

Normal levels of FVIII range from 50% to 150%. Levels below 50% - or half of what is needed to form a clot - determine a person's symptoms.

* Mild hemophilia A: 6% up to 49% of FVIII in the blood. People with mild hemophilia A generally experience bleeding typically only after serious injury, trauma, or surgery. In many cases, mild hemophilia is not diagnosed until an injury, surgery or tooth extraction results in prolonged bleeding. The first episode may not occur until adulthood. Women with mild hemophilia often experience heavy menstrual bleeding, and can hemorrhage (bleed extensively) after childbirth.
* Moderate hemophilia A: 1% up to 5% of FVIII in the blood. People with moderate hemophilia A tend to have bleeding episodes after injuries.
* Severe hemophilia A. <1% of FVIII in the blood. People with severe hemophilia A experience bleeding following an injury and may have frequent spontaneous bleeding episodes - bleeds that occur without obvious cause - often into their joints and muscles. Many males with severe hemophilia are diagnosed due to bleeding after circumcision.

Diagnosis of Hemophilia A

Doctors will perform tests that evaluate how long it takes for the blood to clot to determine if someone has hemophilia. A clotting factor test, called an assay, will show the type of hemophilia and the severity, or how much clotting factor the person produces on their own.

Because of our understanding of hemophilia genetics, most people who have a family history of hemophilia will ask that their baby boys be tested soon after birth to see if they have hemophilia. If there is no family history of hemophilia, people often notice bleeding that takes longer to stop or lots of bruising. Many babies born with severe hemophilia are diagnosed if there is prolonged bleeding after circumcision.

For girls, it often takes seeing worsening of symptoms for the diagnosis process to begin. Most girls are not tested for hemophilia before puberty. Heavy periods are a symptom of a bleeding disorder in women and girls. If there is a known family history, it is important to monitor for symptoms. It is recommended that women who have a family history of hemophilia get tested before getting pregnant, to help prevent complications during childbirth.

The best place for patients with hemophilia to be diagnosed and treated is at one of the federally funded hemophilia treatment centers (HTCs) that are spread throughout the country. HTCs provide comprehensive care from skilled hematologists and other professional staff, including nurses, physical therapists, social workers and sometimes dentists, dieticians and other healthcare providers, including specialized labs for more accurate lab testing.

Find a hemophilia treatment center near you.

How is Hemophilia A Treated?
Learn about treatment options for hemophilia.

Most treatments for hemophilia A focus on replacing the missing protein, FVIII (8), so a person can form a clot, and so reduce or eliminate the bleeds associated with the disorder. Treatments that work to prevent bleeding through new mechanisms have recently come to the market or are in clinical trials. People with hemophilia A have several different medication options for treatment.

Living with Hemophilia A
Explore NHF's Steps for Living to learn more about living with hemophilia A.

There's a lot to know about living with a bleeding disorder like hemophilia A. Visit NHF's Steps for Living to explore resources, tools, tips and videos on living with hemophilia A through all life stages. Organized by life stages, Steps for Living provides information on recognizing the signs of bleeds in children, help on navigating school issues, how to exercise safely, helping teens manage their bleeding disorder, information on workplace accommodations, and much more. There are downloadable checklists, toolkits, videos, and more.

*"Occurrence rates of haemophilia among males in the United States based on surveillance conducted in specialized haemophilia treatment centres," Soucie et al

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Hemophilia A | National Hemophilia Foundation

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Hemophilia A, also called factor VIII (8) deficiency or classic hemophilia, is a genetic disorder caused by missing or defective factor VIII (FVIII), a clotting protein. Although it is passed down from parents to children, about 1/3 of cases found have no previous family history.

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Most people who tend to have hemophilia are born with it. It most almost always is inherited aka (passed down) from a parent to a child.  Both hemophilia A and B are inherited in the same way, because both the genes for factor VIII and factor IX are located on the X chromosome (chromosomes are structures within the body’s cells that contain the genes). 

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Most people who tend to have hemophilia are born with it. It most almost always is inherited aka (passed down) from a parent to a child.  Both hemophilia A and B are inherited in the same way, because both the genes for factor VIII and factor IX are located on the X chromosome (chromosomes are structures within the body’s cells that contain the genes). 

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Centers for Disease Control and Prevention

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Hemophilia is a bleeding disorder in which blood does not clot properly. Blood contains many proteins, called clotting factors, that can help to stop bleeding after injury or surgery. People with hemophilia have low amounts of either factor VIII (eight) or factor IX (nine), key factors responsible for normal blood clotting.

A person's genes provide the instructions on how to make proteins, such as factor VIII and factor IX. In people with hemophilia, there is a mutation (difference from normal) in either the gene for the factor VIII protein or the gene for the factor IX protein. The mutation causes the body to produce too little factor VIII or IX. This change in a copy of the gene making factor VIII or factor IX is called a hemophilia allele.

Most people who have hemophilia are born with it. It almost always is inherited (passed down) from a parent to a child. Both hemophilia A and B are inherited in the same way, because both the genes for factor VIII and factor IX are located on the X chromosome (chromosomes are structures within the body's cells that contain the genes). The X and Y chromosomes determine whether a person's sex is male or female; females have two X chromosomes (XX) and males have one X chromosome and one Y chromosome (XY). There are no genes for clotting factors on the Y chromosome. This means that males only have one allele for factor VIII and one allele for factor IX. Thus, if a male has a hemophilia allele on his only X chromosome, he will have the disorder.

A female inherits two copies of the factor VIII or factor IX gene, one from her mother and one from her father. A female with a hemophilia allele on one X chromosome usually has a normal allele on her other X chromosome that can produce normal clotting factor, so she has some protection against having hemophilia. A female with one hemophilia allele and one normal allele is called heterozygous or a carrier. Some girls and women who are heterozygous have bleeding symptoms, but usually they are milder than those of boys and men with hemophilia. In rare cases, a female who is heterozygous can have bleeding symptoms that are just as serious as those of a male with hemophilia. A female can also have hemophilia if she inherits hemophilia alleles from both of her parents or if she inherits one hemophilia allele and her other X chromosomes is missing or does not work properly. Hemophilia may be hidden in a family for many generations if it passes only through females who do not have bleeding symptoms.

If a mother is heterozygous (a carrier) for hemophilia and the father does not have hemophilia, each son has a 1 in 2 (50%) chance of getting his mother's hemophilia allele and having hemophilia. Each daughter has a 1 in 2 (50%) chance of getting her mother's hemophilia allele and being heterozygous. Overall, there is a 1 in 4 (25%) chance for each pregnancy that the baby will be a son with hemophilia and a 1 in 4 (25%) chance that the baby will be a heterozygous daughter. There is a 1 in 2 (50%) chance that the baby (either a son or a daughter) will not get the hemophilia allele at all and, therefore, can't pass it down to his or her children.

A father who has hemophilia passes his only X chromosome down to all of his daughters, so they will always get his hemophilia allele and be heterozygous (carriers). A father passes down his Y chromosome to his sons; thus, he cannot pass down a hemophilia allele to them. Without the hemophilia allele, the sons will not have hemophilia and can't pass it down to their children. Overall, there is a 1 in 2 (50%) chance that the child will be a son who does not have hemophilia and a 1 in 2 (50%) chance that the child will be a daughter who is heterozygous (a carrier). This is true if the mother does not have a hemophilia allele herself. That would be very rare, unless the parents are related.

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How Hemophilia is Inherited | Hemophilia | NCBDDD | CDC

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Hemophilia is a bleeding disorder in which blood does not clot properly. Blood contains many proteins, called clotting factors, that can help to stop bleeding after injury or surgery. People with hemophilia have low amounts of either factor VIII (eight) or factor IX (nine), key factors responsible for normal blood clotting.

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Researchers are exploring the possibility of treating the disorder with gene therapy. Their strategy is to engineer mesenchymal stem cells, a type of adult stem cell, so that they produce high levels of factor VIII. The cells, acting as a carrier for the gene, would then be transplanted into the patient.

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There is currently no cure for hemophilia, a rare bleeding disorder. Because people with hemophilia have little or no clotting factor, a protein needed for normal blood clotting, they may bleed for a longer time than others after an injury, as well as bleed internally, especially in joints such as the knees, ankles and elbows.

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Names for Hemophilia ,Classic hemophilia ,Factor VIII deficiency ,Christmas disease ,Factor IX deficiency

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Names for Hemophilia ,Classic hemophilia ,Factor VIII deficiency ,Christmas disease ,Factor IX deficiency

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Hemophilia A Classic hemophilia Factor VIII deficiency Hemophilia B Christmas disease Factor IX deficiency Source: National Heart, Lung, and Blood Institute, National Institutes of Health.