Normally, there is a balance between the formation of clots and their destruction. But there are times when that balance is not maintained. Cancer, infections, atherosclerosis, certain medications and injury can all cause blood clots to be formed. But there are some blood disorders which can cause blood clots as well.
Protein C Deficiency
Protein C deficiency is a common blood disorder, according to Dr. J. Ben Davoren in "Pathophysiology of Disease." It is found in one out of every 200 people. Protein C is a protein that is made in the liver, then circulates throughout the bloodstream. Its purpose is to interfere with two substances that will form clots. There are two kinds of protein C deficiency. People who have the kind called type 1 have low levels of protein C. People who have been diagnosed with type 2 have normal levels of the protein, but it is not as active as it should be.
Protein S Deficiency
Protein S is another protein that is needed to stop clots from forming. There are three types of protein S deficiency. People with type 1 have low levels of the protein. Those with type 3 also have low levels, but of a slightly different kind. Anyone who has type 2 has abnormal protein S. Davoren explains that protein C must interfere with one of the clotting substances on a particular spot. But that spot is hidden from protein C. Protein S shows that hidden spot to protein C. Thus, a deficiency or abnormality in protein S means protein C cannot do its job and stop clots from forming.
Disseminated Intravascular Coagulation
Disseminated Intravascular Coagulation is a blood disorder where clots are formed in an uncontrolled manner throughout the blood vessels, according to "The Merck Manual for Healthcare Professionals." Eventually, all of the platelets--the blood cells that help form clots--and clotting factors are used up. At that point, people with DIC will have uncontrolled hemorrhaging. DIC can take weeks or months to develop. But sometimes, it may develop in just a matter of hours.
Antiphospholipid Antibody Syndrome
This is an autoimmune blood disorder where the immune system does not attack foreign substances; it attacks its own body. In this particular disorder, antibodies attack certain proteins. These proteins are supposed to stick to substances in the cell membranes and prevent those cells from clotting. But the antibodies block this process and this leads to the formation of blood clots. The disorder is called antiphospholipid antibody syndrome, because the cell membranes are phospholipid membranes, made of phosphorus and lipids (fats). Pregnant women with this blood disorder are at great risk of losing their babies, according to "Current Medical Diagnosis & Treatment."
References
- "Current Medical Diagnosis & Treatment 2009"; Stephen McPhee, M.D., Maxine Papadakis, M.D.; 2009
- "Pathophysiology of Disease: An Introduction to Clinical Medicine"; Stephen McPhee, M.D., Gary Hammer, M.D., Ph.D.; 2010
- The Merck Manual for Healthcare Professionals: Disseminated Intravascular Coagulation
