CBS.com; CBS All Access; CBS News; CBSN; Watching Live TV. All Access Live TV; TV Provider
Thick blood is caused by a variety of conditions, such as heavy proteins in the blood, too much blood in circulation or a blood clot system imbalance, according to Southeastern Medical Oncology Center. Diseases such as cancer and lupus can also lead to thick blood. Continue Reading.
Cells & protein: Blood may become too thick if there too many cells or too much protein. Increased red cell count, polycythemia, can make the blood viscous. High levels of immunogolobulins, usually due to cancer, also increse viscosity. Rarely leukemia with a very high white cell count may make the blood thick.