Normal blood coagulation is a complex process involving as many as 20 different plasma proteins, which are known as blood coagulation factors. A series of complex chemical reactions using these factors takes place very rapidly to form an insoluble protein called fibrin that stops bleeding. In this disorder, bleeding ranges from mild to severe.

When certain coagulation factors are deficient or missing, the chain reaction does not take place normally. Factor V is rare, and can be caused by inheriting a defective Factor V gene or by acquiring an antibody that interferes with normal Factor V function.

An inhibitor of Factor V can be acquired after giving birth, after surgery, with automimmune diseases and certain cancers, in patients being treated wtih a certain type of fibrin glue, and from unknown sources.

The disease is similar to hemophilia, except bleeding into joints is less common. In the inherited form of Factor V deficiency, a family history of a bleeding disorder is a risk factor.

Excessive bleeding with menstrual periods and after delivery occurs frequently. A family history of a bleeding disorder is a risk factor. Men and women are affected equally. About 1 person per 1 million has the disorder.

• Bleeding into the skin
• Excessive bruising
• Nose bleeds
• Bleeding of the gums
• Excessive menstrual bleeding
• Prolonged or excessive loss of blood with surgery or trauma
• Umbilical stump bleeding

• Factor V assay showing decreased activity
• Slightly prolonged bleeding time (in some people)
• Prolonged partial thromboplastin time
• Prolonged prothrombin time
• Normal thrombin time