Blood Viscosity

How thick or thin your blood is measured using a test for blood viscosity. Blood viscosity is the thickness of blood and is defined as its resistance to flow.  The thicker your blood, the harder your heart must work to provide circulation.  Thick blood can cause a strain on the heart. 

Thick blood can also damage the inner lining of arteries. We don’t tend to think of a liquid as abrasive.  But to delicate artery walls, thick blood can be abrasive, forcing your arteries to shift into defensive mode and form a protective layer of plaque.  This can cause the wall of the arteries to become hardened and thickened, narrowing the passageway for blood to move.

What Makes Blood Thick?

The thickness of blood is determined by four major factors:  the number of red blood cells in the blood (hematocrit), how soft the red blood cell is (deformability), the tendency of the red blood cells to stick together (aggregation), and the plasma content (e.g., cholesterol, fibrinogen, immunoglobulins, etc.).

The test for blood viscosity incorporates all of the cellular and biochemical factors and measures how thick the blood actually is.