Leuk­emia was first descri­bed and named as a dise­a­se in 1845 by Rudolf Virch­ow, a phy­si­ci­an at Ber­lin Cha­ri­té Uni­ver­si­ty Hos­pi­tal. It means “white bloo­ded­ness” and is deri­ved from the mil­ky dis­co­lo­ra­ti­on of the blood in pati­ents which is cau­sed by the increased mul­ti­pli­ca­ti­on of white blood cells. This flood of leu­ko­cytes com­pri­ses imma­tu­re and dys­func­tion­al pre­cur­sors which also pre­vents the for­ma­ti­on of all types of nor­mal blood cells in the bone mar­row. The wide ran­ge of leuk­emia sym­ptoms includes pale­ness, weak­ne­ss, blee­ding ten­den­cy, spon­ta­neous brui­sing and a sus­cep­ti­bi­li­ty to infec­tions, though none are in any way spe­ci­fic to leuk­emia. Depen­ding on the cour­se of the dise­a­se, a distinc­tion is made bet­ween acu­te and chro­nic leuk­emia and many other sub­ty­pes based on the cell types affec­ted and their properties.