blood clotting disorderClotting disorders is a blanket term used to describe a series of disorders that cause excessive clotting of the blood.

These disorders or "thrombophilias" include inherited conditions such as:

  • Factor V Leiden
  • Protein C deficiency
  • Protein S deficiency
  • Anti-thrombin deficiency
  • Prothrombin 20210A mutations

Excessive clotting leads to the formation of blood clots in the blood stream. The development of a blood clot is called thrombosis. Another name for clotting disorders is thrombophilias. The vascular system includes both the venous system (the veins that deliver blood from the tissues to the heart) and the arterial system (the system that delivers blood from the heart to the tissues). Thrombotic episodes may occur in either system. Thrombophilias are inherited and acquired clotting disorders. Inherited are genetic – passed from parent(s) to offspring. Acquired develop after birth and are not associated with genetic causes.

People who experience episodes of thrombosis, either as an isolated event or as a repeated event, may be affected with a thrombophilic disorder. There are people who have inherited the gene, who have an increased tendency for thrombosis, but may never personally experience a blood clot. Many people can have a known thrombophilic condition and never experience a thrombosis.

The symptoms relate to the part of the vascular system in which they occur, the extent of the clot and whether the clot breaks off and travels to another part of the body (e.g., the lungs—pulmonary embolus, the brain—embolic stroke, etc). There are different terms used to further define these thrombotic episodes, such as deep vein thrombosis (DVT) or peripheral vascular disease, when the clots are in the arterial system (usually in the extremities). Although we are now able to determined the underlying cause in some patients and families for this tendency to an increased risk of excessive blood clotting, we are still not able to make this determination in all cases. This means that there is still more to be understood about why some persons and families have thrombophilia.

Recent research shows that these disorders contribute significantly to morbidity and mortality in the United States. Each year, more than 600,000 Americans die from abnormal blood clots.

Even though men and women can have clotting disorders, these conditions pose added difficulties for women because of their relationship to reproductive issues. Women with these disorders can develop serious complications during pregnancy leading to miscarriage. Pregnancy, oral contraceptives and post-menopausal hormone replacement therapy are all triggering events for DVT in women with thrombophilia.

Blood clotting is a normal response to injury or bleeding. The body undergoes a series of changes or reactions to bleeding to promote homeostasis. After bleeding is stopped, fibrinolysis breaks down the clot. Clotting disorders represent a problem with homeostasis, fibrinolysis or a combination of both.


The main symptom of all clotting disorders is irregular clot production or failure to breakdown clots after bleeding is stopped. The specific symptoms will depend upon the disorder. When blood clots develop in blood vessels they are referred to as thrombi (or thrombus – singular). A portion of the clot can break off and enter a vein where it is then called an embolus (emboli – plural). Clots can interrupt blood flow and cause death. Blood clots typically form in the deep veins of the lower legs. These blood clots are called deep vein thrombosis. Symptoms can be localized and include:

  • Redness
  • Pain
  • Swelling

Not all blood clots develop in the lower legs. Blood clots can also form in the arteries of the heart causing heart attack. If a piece of blood clot breaks off and moves to the brain it can cause reduced or blocked blood flow to the brain resulting in stroke. Clots can also affect lung function (pulmonary thrombosis) with symptoms including:

  • Shortness of Breath
  • Sharp, Stabbing Chest Pains
  • Increased Heart Rate
  • Cough
  • Fatigue
  • Dizziness or Fainting

There is a wide range of complications associated with clotting disorders. Some common complications include:

  • Heart Attack
  • Stroke
  • Deep Vein Thrombosis
  • Blocked or Reduced Blood Flow to Organs

Blood clotting disorders are often diagnosed using imaging technology. Diagnostic tests may include:

  • Fibrogen Leg Scanning
  • Venogram
  • Ultrasound with IPG
  • Independent Ultrasound
  • X-Rays
  • CT Scan

Blood tests may also be run to evaluate D-dimer levels, though testing in a hospital setting tends to return less relevant results.


The most common treatment of clotting disorders is prescription blood thinners, including heparin, low molecular weight heparin, Warfarin, Coumadin or other blood thinning medications.

Clotting Disorders and Pregnancy

Warfarin or Coumadin are not safe for use during pregnancy, so women with clotting disorders will be prescribed a pregnancy-safe alternative. Heparin and low-molecular weight heparins are safe for use during pregnancy. Your doctor will discuss the best medication for your clotting disorder during a prenatal examine. If you are taking Warfarin or Coumadin when you become pregnant, contact your physician immediately for an appointment, but do not stop taking the medication without physician consent.

Life Expectancy

With medical intervention via anticoagulants, clotting disorders should not decrease life expectancy. If the condition goes unnoticed and a blood clot causes heart attack, stroke or other serious side effect, premature death could occur.