The blood is then pushed into the lungs where it becomes oxygenated and is them pushed into the left side of the heart for re-circulation. It is literally thicker than water and more adhesive. Water has a viscosity of 1.0. The viscosity of blood ranges from 4.5 - 5.5. As a consequence, it flows more slowly than water.
Blood is also slightly heavier than water.
One of the ways in which we can compare weights of liquids is by measuring the specific gravity. The specific gravity of whole blood varies from 1.052 - 1.061. The specific gravity is slightly higher for men than for women and may vary slightly during a 24-hour period. Plasma or serum, which is the liquid portion of the blood, has a specific gravity of 1.022 - 1.031. We can observe these two portions of blood by drawing blood into a tube and allowing it to sit over a period of time or by centrifuging the sample.