blood dissease

Introduction to Hematology
Diseases of White Blood Cells
As you might suspect from the number of types of white blood cells (also known as leukocytes), and the number of functions, there are many diseases that involve these cells. The term leukemia refers to a great number of these diseases and generally describes cancerous conditions where there are too many leukocytes in the blood.

There are many leukemias. In all of them, one cell line (sometimes lymphocytes, sometimes monocytes, sometimes one of the other cell lines) begins uncontrolled growth. The cells begin to fill the marrow (as shown here) crowding out other cell lines and pouring into the bloodstream.

Other, non-cancerous events may trigger higher than normal numbers of white cells. They may be made in response to infection, as shown here on the left. Compare the concentration of neutrophils to the normal smear on the right.