Combined factor V and factor VIII deficiency is a blood-clotting disorder that results in excessive or prolonged bleeding after an injury or surgery. Factor V and factor VIII are two of 13 proteins involved in proper formation of blood clots. Blood clots are needed to heal wounds, form scabs, and stop bleeding. When factor V and factor VIII levels are low or absent, the blood does not clot correctly, leading to excessive bleeding. Combined factor V and factor VIII deficiency runs in families and is an autosomal recessive disorder, meaning it is a less common disorder and parents with the disorder may not necessarily pass it on to their children. The main symptom of combined factor V and factor VIII deficiency is excessive and abnormal bleeding. This may occur after childbirth, surgery, trauma, and with menstruation (periods). Bleeding can also occur in the muscles, joints, the mouth, the gut, or, infrequently, the brain. Easy bruising and nosebleeds are also common. Combined factor V and factor VIII deficiency can be diagnosed by a physician using blood tests. Treatment for combined factor V and factor VIII deficiency is largely based on controlling bleeding and treating any underlying conditions that contribute to excessive bleeding. When necessary, excessive bleeding can be stopped with infusions of clotting factorsinto the blood.