Blood needs to remain fluid in our bodies.
Blood carries nutrition and oxygen to our tissues and must reach even the smallest blood vessels in our muscles, brain, and other organs. This requires a complex biochemical system that allows blood to remain fluid even as it passes through vessels that are only microscopic in size. On the other hand, it is obvious that blood must be able to quickly clot, turning from a fluid, life-sustaining liquid to a solid clot rapidly when blood vessels are injured by trauma. If blood fails to clot efficiently, patients bleed excessively. If blood clots too efficiently, inappropriate or excessive clots may form.