FAQ: Are Anticoagulants and blood thinners the same thing? How do they “thin” the blood?
Last updated: October 18, 2022
We’ve posted a new FAQ and answer under Drug Therapies and Medicines in our section:
Are Anticoagulants and blood thinners the same thing? How do they thin the blood?
Since A-Fib increases your risk of clots and stroke, blood thinners are prescribed to prevent or break up blood clots in your heart and blood vessels and thereby reduce your chance of an A-Fib-related ischemic stroke (blood vessel blocking clot).
Although referred to as “blood thinners”, anticoagulants don’t substantially affect the “thickness” or viscosity of your blood. (A “D-dimer test” is sometimes used to test for blood clotting disorders.)

Anticoagulant Warfarin
There are two main types of blood thinners: anticoagulants and antiplatelet agents. They work differently to accomplish the same end effect.
Anticoagulants work chemically to lengthen the time it takes to form a blood clot. Bleeding events are common complications of direct oral anticoagulants (DOACs).
Common anticoagulants include warfarin (Coumadin), Heparin and the NOACs such as apixaban (Eliquis).


Antiplatelets prevent blood cells (platelets) from clumping together to form a clot.
Common antiplatelet medications include aspirin, ticlopidine (Ticlid) and clopidogrel (Plavix) .
There is currently no standard measurement for blood viscosity—the thickness or stickiness of one’s blood, how well your blood flows through your body, especially through the capillaries which are very small. When you get a physical from your GP, you will usually not see a measurement of blood viscosity. But blood viscosity can be somewhat measured by other means. See https://a-fib.com/noacs-why-no-way-to-measure-their-effectiveness/
Note: To read about ‘clot buster’ drugs or treatments that could save you from a debilitating stroke, see my article: Your Nearest ‘Certified Stroke Center’ Could Save Your Life.