Factor II deficiency is a blood clotting (coagulation) problem caused by a lack of a substance (prothrombin) that is needed for blod to clot.

When you bleed, the body launches a series of activities that help the blood clot. This is called the coagulation cascade. The process involves special proteins called coagulation factors. (Factor II is a coagulation factor.) Each factor's reaction triggers the next reaction. The final product of the coagulation cascade is the blood clot.

When certain coagulation factors are too low or missing, the chain reaction does not take place normally. In this disorder, bleeding ranges from mild to severe.

A congenital factor II deficiency is a very rare disorder that runs in families (inherited). It results in poor blood clotting. Both parents must be carriers to pass it to their children. A family history of a bleeding disorder is a risk factor.

Acquired factor II deficiency is common and results from a lack (deficiency) of vitamin K, severe liver disease, and use of drugs that prevent clotting (anticoagulants). Risk factors for vitamin K deficiency are long-term use of antibiotics, bile duct obstruction, and poor absorption of nutrients from the intestinal tract (intestinal malabsorption). Some newborns are born with vitamin K deficiency.

• Umbilical cord bleeding at birth
• Nose bleeds
• Abnormal menstrual bleeding
• Abnormal bleeding after delivery
• Bleeding after trauma
• Bleeding after surgery
• Bruising

• Prolonged prothrombin time
• Longer partial thromboplastin time
• Factor II assay showing lower activity

Blood loss can be controlled by getting fresh or frozen plasma or concentrates of clotting factors into the blood. If the disorder is caused by a lack of vitamin K, then the person will take vitamin K. Diagnosing a bleeding disorder is important so that the doctor can take extra care if the patient needs surgery.

You can ease the stress of illness by joining a support group where members share common experiences and problems. See hemophilia - resources.

This is a life-long bleeding disorder if you get it from your parents. If it is caused by liver disease, the outcome depends on how well you control the liver problem. Taking vitamin K will treat vitamin K deficiency.

Bleeding into the brain or skull can occur.

Go to the emergency room or call the local emergency number (such as 911) if you have unexplained or long-term blood loss or if you can't control the bleeding.

Genetic counseling may be helpful for disorders that start at birth (congenital). When a lack of vitamin K is the cause, the use of vitamin K can help. Long-term antibiotic use may help prevent problems.

Hoffman R, Benz E, Shattil S, Furie B, Cohen H. Hematology: Basic Principles and Practice. 4th ed. Philadelphia, Pa: Churchill Livingstone; 2004.

McPherson RA, Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. St. Louis, Mo: WB Saunders; 2006: 741.