Hello my friend... Your question is with very less information...And the discrimination given I.e thick blood is your subjective feeling... I would like to know about other possible symptoms...it may be due to hyperviscosity...result from increased cellular blood components (typically white or red blood cells) in hyperproliferative states such as the leukemias, polycythemia, and the myeloproliferative disorders....Consult nearest physician they will do the needful.