In both the Rai and Binet systems (the US uses the Rai system primarily), staging is based on the progression of objective signs of CLL which is quantitative. It is what can actually be observed and measured, such as the presence of enlarged lymph nodes and then both the presence of enlarged lymph nodes and spleen. The latter indicates progression. The CBC and platelet count figure in here, too. Since measurability is scientific and concrete, it's definitive. Of course, the experts who devised these systems somewhere defined where the cutoff to the next stage should be.

The subjective ( actual symptoms) are actually not included. Everyone's symptoms are so different. I could be in stage 0 (no signs of disease, lymph nodes normal, bloodwork close to normal) and feel tired and you could have the same bloodwork and lymphnode configuration and feel great. We both are in Stage 0 although we feel different.