Certain ethnic races (particularly Caucasian) may have a genetic predisposition towards thick blood. Defects in the coagulation genes adversely affect the capability of the body to turn off the switch that activates the clotting process. These defects may also affect the body’s ability to clean up the fibrin deposits formed as a result of the clotting process.
Thick blood may also be caused by the presence of harmful pathogens such as fungi, viruses, bacteria, and parasites. These pathogens can actually activate a coagulation response in the body as a way to avoid being attacked by the body’s immune system. Soluble fibrin monomer (SFM), a clotting agent, lines the capillaries with fibrin making it impossible to transfer oxygen and nutrients to body tissues. A lack of oxygen and nutrients then creates an ideal environment for these pathogens to survive and cause illness. The blood must first be thinned to expose the pathogens before they can be eradicated.
Heavy metal toxicity or exposure to environmental toxins can also activate unusual production levels of soluble fibrin monomer (SFM). Stress and trauma have also been known to cause thick blood.