Lymphocytes are divided into three main categories: T cells, B cells and natural killer (NK) cells, which are the main immune cells in the body, and observing changes in their numbers helps to understand the state of the body’s immune function. High lymphocytes include both absolute and relative increases.
Absolute increase: mainly seen in infectious diseases and mainly viral infections, such as: infectious mononucleosis, measles, chickenpox, mumps, viral hepatitis, epidemic hemorrhagic fever, but also in whooping cough, tuberculosis, brucellosis, syphilis, etc. The number of lymphocytes increases in these conditions, as does the percentage. In addition, lymphocytosis can also occur in a variety of lymphomas (including acute lymphocytic leukemia, chronic lymphocytic leukemia, and some lymphomas), during recovery from acute infectious diseases, and after transplant rejection.
Relative increase: The relative increase in lymphocyte ratio is mainly due to the decrease in the number of other cells due to some causes, but the absolute value of lymphocytes is not increased, such as aplastic anemia, granulocytopenia, granulocyte deficiency, etc.
Therefore, the above causes may lead to an absolute or relative increase in lymphocytes, but a high lymphocyte alone is not sufficient to determine the diagnosis, which needs to be combined with clinical symptoms and other relevant laboratory tests.