Inherited
Hemophilia A (Factor VIII deficiency) -- X-chromosome linked bleeding disorder that occurs primarily in males. The first bleeding episode may be with circumcision or other procedures as an infant. The severity of the bleeding caused by a factor VIII deficiency depends on its activity level. If it is very low, it may cause severe life-threatening bleeding; if it is moderate, it may only cause mild to moderate bleeding, becoming an issue primarily when having surgery or dental procedures.

von Willebrand’s disease -- relatively common, resulting from defective or decreased von Willebrand factor. Von Willebrand factor is a protein that adheres platelets to the site of a blood vessel injury. It is associated with factor VIII: if VIII is deficient, then vWF may be affected.

Other factor deficiencies -- II, V, VII, X, IX, (Hemophilia B, also called Christmas disease)

Acquired:

• Liver dysfunction or disease
• Vitamin K deficiency
• Fat malabsorption
• Snake venom
• Therapy for malignancies
• Factor inhibitors (antibodies that target a specific clotting factor, such as factor VIII, decreasing its activity and making factor replacement more of a challenge)
• Anticoagulant drugs: such as coumadin (warfarin) or heparin; these drugs are used to treat clotting disorders but in excessive amounts may cause bleeding.
• Some bacterial infections
• Disseminated intravascular coagulation (DIC), may cause both bleeding and clotting. It is usually an acute condition, may be from a complicated childbirth, from an endotoxin produced during a severe infection, or due to certain cancers such as leukemia. DIC causes tiny clot formation throughout the body, using up clotting factors at an accelerated rate, leading to excessive bleeding.