Low CD3CD4 percentage can be seen in chronic lymphocytic leukemia, acute leukemia, lymphoma, myeloma, malignant solid tumors (stomach cancer, intestinal cancer, etc.) and other diseases. Low CD3CD4 percentage often indicates low immunity, and there are many diseases that may cause low CD3CD4 percentage, such as chronic lymphocytic leukemia, acute leukemia, lymphoma, myeloma, malignant solid tumors (stomach cancer, intestinal cancer, etc.). The CD3CD4 percentage of these patients is often persistently reduced. When the human body stays up late for a long time and is overly fatigued, a temporary low CD3CD4 percentage may also occur, which can gradually return to normal after sufficient rest, and is a physiological decrease. It is recommended that patients with low CD3CD4 percentage should consult a doctor in time, complete the banana examination to clarify the specific cause of the disease, and then treat the cause of the disease, and pay attention to personal hygiene, dietary hygiene and environmental hygiene in order to prevent infections from occurring.