Can leukemia be detected through a routine blood test?

It is increasingly common to hear about someone nearby being diagnosed with leukemia, indicating a rising incidence of this disease. So, can routine blood tests detect leukemia?

Can leukemia be detected by a routine blood test?

A routine blood test cannot definitively diagnose leukemia, but it may provide suggestive clues pointing toward the possibility of leukemia. Blood contains three main types of blood cells: white blood cells (WBCs), red blood cells (RBCs), and platelets. If WBC counts are markedly elevated or decreased—especially when accompanied by reduced hemoglobin levels and low platelet counts—leukemia should be considered. Conversely, if all three cell lineages appear entirely normal, leukemia is highly unlikely. If abnormalities are observed in any blood cell type and further evaluation for leukemia is warranted, the simplest next step is peripheral blood smear analysis (differential count). The presence of blast or immature cells on the smear strongly suggests leukemia.

Leukemia suppresses bone marrow hematopoietic function, leading to reductions in normal blood cell counts. Leukemic cells proliferate excessively within the bone marrow, thereby inhibiting normal hematopoiesis. This manifests clinically as decreased numbers of normal white blood cells, red blood cells, and platelets. Reduced WBC counts compromise immune function, increasing susceptibility to infections such as pneumonia or perianal abscesses.

Note: In hot weather, wounds in patients with leukemia tend to heal poorly; therefore, elective surgeries and invasive procedures should be minimized whenever possible. Additionally, coagulation dysfunction is common in leukemia, so accidental injuries should be avoided. We hope this information is helpful to you.