Mild, Moderate, and Severe Hemophilia A

Hemophilia A is a rare condition where the blood doesn’t clot the way it should. This happens because the body doesn’t make enough of a clotting protein called Factor VIII. Without this protein, bleeding can last longer than normal after an injury or surgery, or can even happen without a clear cause in cases of severe hemophilia.

Hemophilia A is caused by a deficiency in Factor VIII, one of the proteins that helps blood to form clots. Based on the level of Factor VIII protein in the blood, the 3 levels of hemophilia A severity are:

• Mild
• Moderate
• Severe 

Hemophilia should be taken seriously, irrespective of the severity. Below is a breakdown of the symptoms associated with each level.

People with mild hemophilia A have Factor VIII levels that are 5% to <40%. Mild cases make up around one-quarter of all hemophilia A cases.

• Prolonged periods of bleeding following significant injury, surgery, or dental work
• Heavy menstrual bleeding and postpartum hemorrhage in women with mild hemophilia
• Rare spontaneous bleeds

Moderate hemophilia A, with Factor VIII levels at 1% to 5%, accounts for 15% of all hemophilia A cases.

• Easy bruising
• Excessive and prolonged bleeding following injury, surgery, or dental work
• Occasional spontaneous bleeding

Severe hemophilia A, marked by Factor VIII levels of less than 1%, represents 60% of hemophilia A cases. With treatment advances, severe hemophilia life expectancy has improved, but early and consistent care is critical. 

• Frequent spontaneous bleeding
• Frequent bleeding into joints that can lead to chronic pain and joint damage

Hemophilia A severity levels are determined by the level of Factor VIII protein in the blood. Doctors can measure this with a blood test. Since Factor VIII helps blood to form clots, the less Factor VIII protein a person with hemophilia A has, the more severe their condition will be.

Hemophilia A is treated by replacing the missing Factor VIII protein, or by replacing the function of it, so that the blood can clot properly. Several treatment options are available for this, and they vary based on the severity of the case. For more serious cases, patients may receive comprehensive care and individualized treatment plans from their healthcare team, including prophylaxis and on-demand treatments, to prevent and manage bleeding episodes effectively.

Treatment is tailored to severity and daily life needs.

• Prophylaxis: Regular infusions to prevent bleeding before it starts. This is recommended for people with moderate to severe hemophilia A
• On-demand therapy: Administered after a bleeding episode starts—commonly used in mild to moderate cases or before certain medical procedures

People with cases of more severe hemophilia A often receive comprehensive care through a hemophilia treatment center, where a care team can help address all issues related to the disorder.

It is crucial to recognize the unique challenges faced by people with hemophilia and to continue to advocate for better care and understanding for patients living with this condition.

• The 3 levels of hemophilia A severity—mild, moderate, and severe—are determined by the levels of Factor VIII protein in the blood
• Symptoms and treatment can vary depending on the severity of each person’s condition
• Regardless of severity, hemophilia A requires ongoing care to help patients lead active, healthy lives