What is Thrombophilia?

Thrombophilia is a term used to describe a group of conditions leading to an increased tendency to develop dangerous blood clotting in veins or arteries. These conditions can be divided into two types: 1) those present at birth (congenital or inherited) or 2) those that may occur as the result of another condition (acquired).

What is a Clot?

The blood clotting system is activated when a blood vessel is injured. Platelets circulating nearly are the “first responders.” Platelets stick to the injured vessel wall and recruit more platelets to the site. This clumping or aggregation of platelets forms a temporary plug that protects the vessel wall from further bleeding. At the same time, proteins are activated to make a tissue glue called fibrin. Fibrin is laid down at the site of the platelet plug, making it secure. Over time, scar tissue forms to complete the healing process.

What Keeps Blood from Clotting?

The clotting process is very efficient, ensuring that haphazard clotting does not occur throughout the blood stream. Blood plasma contains many proteins that either inhibit the formation of a clot or dissolve the clot by breaking down the fibrin. Thus, a delicate balance of clotting and bleeding results. This allows blood clots to form appropriately to injury to the vessel wall and to breakdown the clot when it is no longer needed.

Where do Clots Occur?

Clots may occur in either the venous system (veins that deliver blood to the heart) or the arterial system (the system that delivers blood from the heart to the tissues). Symptoms of a blood clot depend upon the part of the vascular system in which they occur, the extent of the clot and whether the clot breaks away from the vessel wall and travels to another part of the body. 

What Conditions Can Lead to Acquired Thrombophilia?

Many conditions increase the risk for developing a dangerous clot. These include physiological factors (surgery, increased age, bed rest, obesity, pregnancy), medications (birth control pills, some cancer medications) and other diseases (cancer, diabetes, systemic lupus). These risk factors are cumulative, meaning that multiple conditions that could lead to inappropriate clotting provide a greater risk of thrombosis.

What are the Types of Inherited Thrombophilias?

Certain genetic mutations have been associated with increased risk of bleeding. These include Factor V Leiden (resistance to Protein C), Protein C deficiency, Protein S deficiency, Antithrombin III deficiency, Prothrombin 20210 mutation (elevated prothrombin levels) and Homocystinuria. Presence of the inherited predisposition alone seems to only be a small risk for certain families. However, the presence of an additional acquired risk factor (mentioned above) poses a greater risk for dangerous clot formation.   

What Kinds of Treatment are Available?

Individuals with thrombophilia may receive medications that affect the coagulation system. One class of medications decreases the person’s ability to make a clot. These include aspirin, heparin, low molecular weight heparin and coumadin. Another class of medications called thrombolytic agents is used to dissolve clots under certain circumstances. Individuals with thrombophilia may receive these medications only during a time of increased risk of thrombosis or for a prolonged period of time, even a lifetime.