Proper blood flow through the body’s thousands of miles of arteries and veins is vital to life. On the other hand, the body must also be able to stop blood flow in instances where blood vessels are damaged. This balance of free-flowing and clotting blood can be manipulated medically to treat diseases in the blood system.
The process that leads to blood clotting (coagulation) is complex, involving the blood cells, blood vessel walls and many chemicals traveling in the blood stream. There are medical conditions wherein it is desirable to prevent the blood from clotting (anti-coagulation). You may have seen the myriad of commercials for drugs like Xarelto, Eliquis and Plavix on TV. These medications are given specifically to keep the blood “thin,” that is, unable to readily clot.
For various reasons, some individuals will develop abnormal blood clots in parts of the body. The condition of a blood clot (thrombus) forming in the leg is called deep vein thrombosis (DVT). A clot can also form inside the heart in those who have atrial fibrillation. Still, others can have clots form in the blood vessels of the brain. Moreover, blood clots can detach and travel in the vascular system. These are called emboli.
The danger is that clots can impair blood flow. A blood clot that has formed in a vein of the leg can travel to the heart and into the lung. This pulmonary embolus can lodge in the vessels of the lung and prevent blood flow to lung tissue. This leads to lung tissue loss, disruption of oxygen transfer and, in severe cases, death. The same is true of other critical areas of the body, including the brain and heart, leading to strokes and heart attacks, respectively.
Blood thinners are used in individuals who are at risk for clot formation or who have had clots in the past. For example, an individual with atrial fibrillation may be put on a blood thinner such as Coumadin (warfarin) or one of the other products listed above to prevent clots from forming inside the heart. Fibrillation means the heart is basically “twitching” and not moving blood as effectively through the heart. This means blood can pool inside the atrium of the heart, and a clot can form.
People who are immobilized for prolonged periods of time may also be given blood thinners to prevent blood clots. Those who have undergone major surgery or have had major trauma and are confined to bed are usually given heparin, another blood thinner that can be given via shot or intravenously, or other blood thinners.
Some medical conditions can predispose individuals to easy clotting of the blood. Pregnancy is the most common state. Certain types of cancer can also cause the blood to become easier to clot.
As I have mentioned, there are a host of medications that are used to prevent blood clotting. All of these drugs interfere in some way with the clotting cascade, the multi-step pathway to coagulation. One of the most well known and commonly used blood thinners is aspirin. Aspirin interferes with the platelets’ ability to adhere to blood vessel walls and other platelets, thus prolonging the bleeding time.
A final important point: many blood thinners have interactions with other types of prescription and over-the-counter medications. If you are on a blood thinner, always check with your doctor before taking any new medications, herbs or supplements.
The content in this column is for informational purposes only. Consult your physician for appropriate individual treatment. Dr. Reynolds practices Family Medicine in Chesterfield.
