What is hemophilia?
Hemophilia is a bleeding disorder, usually inherited, in which the blood does not clot properly. It is caused by a missing clotting factor or reduced activity of that factor. As a result, bleeding may last longer than usual or occur without an apparent cause.
The two main forms are hemophilia A, involving factor VIII, and hemophilia B, involving factor IX. They can look alike clinically; laboratory tests distinguish between them.
Hemophilia does not mean that every small cut bleeds more quickly. The main problem is that the clot does not become stable enough, so bleeding may continue, start again, or occur inside joints and muscles.
📌 Statistical note: Hemophilia affects about 1 in 5,000 male births worldwide. Hemophilia A is more common than hemophilia B. One global estimate suggests that approximately 1.1 million males live with hemophilia, many of them undiagnosed.
When a blood vessel is injured, the blood forms a clot and bleeding stops. This happens with the help of proteins called clotting factors, which work together to control bleeding.
Clot formation involves several steps. First, platelets cover the injury and form an initial layer. Clotting factors then activate one after another and reinforce this layer with a network of fibrin, which stabilizes the clot.
Factor VIII and factor IX are important parts of this process. When either is missing or has low activity, the clot does not stabilize properly. Bleeding may therefore continue for longer or begin again after it appeared to stop.
Over time, repeated bleeding into the same joint can damage its lining, called the synovium, and its cartilage. This may cause chronic pain, stiffness, and restricted movement.
Hemophilia A and B are usually inherited through the X chromosome. For this reason, hemophilia is diagnosed more often in males, while females are more often carriers. However, female carriers may also have low factor levels and bleeding symptoms.
A male with hemophilia does not pass the affected X chromosome to his sons, but all his daughters inherit it.
A female carrier has a 50% chance of passing the affected X chromosome to each child. Sons who inherit it may have hemophilia; daughters may be carriers or have symptoms.
Hemophilia can also occur without a previous family history because of a new genetic change.
Family history is the main risk factor for inherited hemophilia. In affected families, genetic counseling and testing can help assess the risk of passing it on.
There is also acquired hemophilia A, which is not inherited. In this form, the immune system produces antibodies that interfere with factor VIII. It can occur in both men and women, more often at an older age or after childbirth.
There are two main forms based on the factor affected:
Severity is determined by the level of factor activity in the blood. In general, the lower the level, the greater the risk of spontaneous bleeding. There are three categories:
📌 Statistical note: Approximately half of people with hemophilia A have the severe form. In these cases, bleeding often occurs in the joints.
Acquired hemophilia A
Acquired hemophilia A is an autoimmune disorder, rather than an inherited one, in which antibodies inhibit factor VIII. It affects both sexes, particularly older people and women after childbirth. It should be considered when someone with no previous bleeding history suddenly develops large bruises, soft-tissue hematomas, or prolonged bleeding.
The main sign is bleeding that lasts longer than usual or occurs without an apparent cause. Joints and muscles are among the most commonly affected sites. Symptoms depend on factor activity and can range from mild to life-threatening.
In infants with severe hemophilia, signs may appear during the first 18 months, including bruising or bleeding after mouth injuries or procedures. Mild hemophilia may go undetected until an injury, dental procedure, or surgery.
Bleeding inside the head is rare but is among the most serious complications. It may occur even after a minor injury and sometimes develops after a delay. Any head injury in a person with hemophilia requires immediate assessment.
⚠️ Seek medical help immediately after a head injury or if there is a severe headache, vomiting, drowsiness, confusion, bleeding that will not stop, blood in the urine or stool, or sudden pain and swelling in a joint or muscle.
Diagnosis is based on the personal and family history of bleeding, a clinical examination, initial clotting tests, and measurement of the activity of the relevant factor. Tests may include:
Acquired hemophilia A may be suspected when a person without a previous bleeding history develops large bruises, hematomas, or prolonged bleeding. Assessment then includes testing for factor VIII inhibitors.
Treatment aims to control and prevent bleeding, protect the joints, and support an active life. It may include intravenous replacement of the missing factor using plasma-derived products processed for viral safety or recombinant factors produced in a laboratory. The main approaches include:
Acquired hemophilia A requires separate treatment to control bleeding and suppress the antibodies that interfere with factor VIII. Hemophilia care is provided through specialized centers, with treatment tailored by a doctor. With current treatments, people with hemophilia can live long and active lives.
Bleeding inside the skull or internal organs, and anemia caused by blood loss, can be serious complications.
Repeated, untreated bleeding can also have lasting effects:
In daily life, people with hemophilia should follow the preventive treatment schedule prescribed by their doctor and should not stop it on their own. Regular physical activity helps strengthen muscles and protect joints. Lower-impact activities such as swimming, walking, or cycling with protective equipment may be preferred; contact sports should be discussed with the medical team. Dental health is important, and the dentist or surgeon should always be told about the diagnosis before a procedure.
Medicines that may increase bleeding, such as aspirin and nonsteroidal anti-inflammatory drugs, should not be used without medical advice. It is useful to carry a card or document stating the diagnosis and the factor affected for emergencies. Regular visits to a specialized center help assess joint health and monitor treatment.
Unusual or repeated bleeding should not be ignored. A hematology consultation is recommended if you or your child has:
Assessment is also important when there is a family history of hemophilia. Female carriers should have their factor level assessed, particularly before surgery, during pregnancy, and before childbirth, so the bleeding risk can be planned for appropriately.
Hemophilia A and B are inherited bleeding disorders that require an accurate diagnosis, patient education, and regular follow-up with a hematologist. Factor VIII or IX activity testing establishes the type and severity, while genetic testing may help families and carriers.
With prophylaxis and modern treatments, people with hemophilia can live long and active lives. Recognizing bleeding early, treating it without delay, and receiving care from a specialized center help protect the joints and prevent serious complications.
Is hemophilia dangerous?
It can be serious, especially in severe forms or when bleeding affects the head or internal organs. With prophylaxis and specialist care, most people can lead active lives.
Can it be completely cured?
Inherited hemophilia is a lifelong condition. Modern treatments can control it and prevent many bleeding episodes. Acquired hemophilia A is treated differently and may improve with appropriate treatment.
Can it be managed without medication?
People with mild hemophilia may not need daily treatment, but procedures and bleeding episodes should be planned with a doctor. Severe forms usually require prophylaxis.
How long does treatment last?
Care for inherited hemophilia continues throughout life. The treatment schedule and frequency vary according to severity, age, and individual response.
Can bleeding episodes recur?
Yes. Without prevention, bleeding may recur in the same joint or muscle. Prophylaxis and early treatment substantially reduce this risk.
When is factor VIII or IX activity measured?
It is measured when hemophilia is suspected to confirm its type and severity, before certain procedures, or when the doctor assesses response to treatment.
What foods or activities should be avoided?
There is no special diet, but maintaining a healthy weight helps protect the joints. Activities with a high risk of injury and medicines that affect clotting should be discussed with the hemophilia team in advance.
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📌 Reviewed by Dr. Irma Lapaj, Hematologist, Klinika Kajo.
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