Hemophilia and other bleeding disorders are often caused by problems with clotting factors — specialized proteins that help the blood clot. Blood clotting is a natural process that stops bleeding by forming a protective “plug” at the site of an injury. In people with bleeding disorders, this process is either slowed or doesn’t work properly, leading to excessive or prolonged bleeding.

These disorders are classified by which clotting factor is too low or ineffective. In some cases, hemophilia types are also categorized by the underlying cause of the disorder. Knowing which type of bleeding disorder a person has is crucial for determining the most effective treatment.

Types of Bleeding Disorders

Most bleeding disorders are genetic conditions, meaning they are inherited and passed down through families. Some, however, are acquired, meaning they develop later in life due to other factors like autoimmune conditions, certain medications, or underlying health issues. In most bleeding disorders, severity is determined by the level of clotting factor activity — lower levels typically indicate more severe disease.

Von Willebrand Disease

The most common of all bleeding disorders is von Willebrand Disease (VWD). People living with VWD either lack von Willebrand factor or have low levels of it, which can lead to reduced levels of factor VIII. (You will usually see Roman numerals in any discussion of clotting factors.) Around 1 in 100 people in the United States has a form of VWD. There are three subtypes of von Willebrand disease that describe severity: type 1, type 2, and type 3.

Type 1 is the mildest and most common form of VWD, accounting for up to 85 percent of cases. This type involves low levels of VWD and they may also have low levels of factor VIII.

In type 2, clotting factors may or may not be low, but they do not work effectively. Type 2 accounts for about 20 percent of cases, and it has several subtypes.

Type 3 VWD is the most severe type, involving very little or no von Willebrand factor. Only around 3 percent of people with VWD have type 3.

Hemophilia A

In hemophilia A, also known as classic hemophilia, people lack or have low levels of factor VIII, a protein crucial for blood clotting. About 1 in 5,617 males have hemophilia A at birth, according to the Centers for Disease Control and Prevention (CDC). About 60 percent of people with hemophilia A have the most severe form of the disease, meaning they have very little to no factor VIII and thus experience frequent spontaneous bleeding episodes.

Hemophilia B

People with hemophilia B – also called Christmas disease – lack factor IX. About 5 in 100,000 males are born with hemophilia B worldwide, according to StatPearls.

A rare form called hemophilia B Leyden affects 3 percent of those with hemophilia B. This form causes frequent bleeding episodes during childhood, which often subside after puberty. People with hemophilia B Leyden have extremely low levels of factor IX in childhood, but they gradually increase as the person ages. By adulthood, some may reach near-normal factor IX levels and no longer require treatment for their bleeding disorder.

Acquired Hemophilia

Some people are not born with hemophilia but develop it later in life due to another health condition or certain medications. This is known as acquired hemophilia, and it can be very severe. Globally, acquired hemophilia affects 0.2 to 1 people per 1 million per year. Unlike most other bleeding disorders, acquired hemophilia may sometimes resolve if the underlying cause — whether a health condition or medication trigger — is successfully treated.

Factor I Deficiency

Factor I deficiency, also known as congenital fibrinogen deficiency, production or function of fibrinogen, a protein crucial for blood clotting. The severe form, congenital afibrinogenemia, affects about 1 in 1 million people worldwide.

Factor II Deficiency

Factor II deficiency, also known as prothrombin deficiency, affects approximately 1 in 2 million globally. The condition may be inherited or acquired due to factors such as liver disease, vitamin K deficiency, or long-term use of antibiotics. Factor II deficiency is usually mild, though more severe cases can occur.

Factor V Deficiency

Factor V deficiency affects approximately 1 in 1 million globally. People who have the most severe form of this deficiency will likely experience symptoms starting in childhood, including frequent nosebleeds, easy bruising, and prolonged bleeding after injuries or surgeries.

Factor VII Deficiency

Factor VII deficiency affects approximately 1 in 300,000 to 500,000 in the general population. The severity of the condition can vary based on factor levels, with some individuals experiencing mild to severe symptoms, while others may have none. Factor VII deficiency can be inherited or acquired due to liver disease, vitamin K deficiency, or the use of blood-thinning medications.

Factor X Deficiency

Approximately 1 in every 500,000 to 1 million people worldwide have factor X deficiency, which can range from moderate to severe. Symptoms can include prolonged bleeding after injuries, easy bruising, and excessive bleeding. Factor X deficiency is also known as Stuart-Prower deficiency.

Factor XI Deficiency

Factor XI deficiency, also known as hemophilia C, affects approximately 1 in 100,000 people in the United States. This condition typically ranges from mild to moderate in severity. Affected individuals often experience prolonged bleeding after surgeries or injuries.

Factor XIII Deficiency

Factor XIII deficiency can range from mild to severe. This condition is also extremely rare, affecting about 1 in 2 million to 5 million people globally. Some researchers believe this condition may be underdiagnosed, as its symptoms can be subtle or mistaken for other bleeding disorders.

Combination Deficiencies

In rare cases, some people have deficiencies of more than one clotting factor. The most common combination deficiency involves factors V and VIII. In this condition, the body produces both factors but cannot properly transport them into the bloodstream.

Extremely rarely, some babies are deficient in all clotting factors that are dependent on vitamin K, which include factors II, VII, IX, and X. This condition, known as vitamin K deficiency bleeding, may be acquired due to liver failure, lack of vitamin K, or if the mother takes certain blood-thinning or anti-seizure medications. Vitamin K deficiency bleeding occurs in approximately 1 in 14,000 to 25,000 newborns. It’s preventable with a vitamin K injection at birth.

Bleeding Disorder Types and Treatments

The type of bleeding disorder you or your loved one has is central to the treatment plan your healthcare team will develop. Treatments may include clotting factor replacement therapies, lifestyle changes, or medications that help prevent and manage bleeding episodes. When discussing treatments, ask questions and be open about how your condition is progressing, any new symptoms or side effects, and whether your current plan is meeting your needs. This collaborative approach ensures that your treatment remains effective and is tailored to your unique circumstances.

Talk With Others Who Understand

On MyHemophiliaTeam, the social network for people with hemophilia and their loved ones, more than 6,000 members come together to ask questions, give advice, and share their stories with others who understand life with hemophilia.

Are you living with hemophilia? What type of hemophilia do you have? Share your experience in the comments below, or start a conversation by posting on your Activities page.