Q: How do “blood thinners” reduce blood viscosity?

A:  Blood Thinners have no impact on the viscosity (thickness) of blood.  Instead, blood thinners prevent the blood from clotting or existing clots from getting larger.  They do not dissolve existing clots.

Blood thinners fall into two categories:  anticoagulants and antiplatelets. Anticoagulants, such as heparin, lengthen the time it takes to form a clot.  Antiplatelets, such as aspirin, prevent blood cells called platelets from clumping together to form a clot.Blood thinners are prescribed to treat some types of heart disease, to those with a higher risk of stroke, or a higher risk of clotting.

Although beneficial, blood thinners may increase the risk of serious bleeding due to cuts or injuries.  Our first line of defense should be proper nutrition and exercise to combat diseases.

The following websites were used in answering the question:
http://www.webmd.com/dvt/dvt-treatment-tips-for-taking-heparin-and-warfarin-safely
https://www.nlm.nih.gov/medlineplus/bloodthinners.html