AIDS patients are very prone to catching colds because HIV mainly destroys the immune system of the human body, and HIV mainly attacks the most important CD4T lymphocytes in the immune cells of the human body. After the immune system has been destroyed in large quantities, the immune system of the body is extremely lowered, and colds as well as all kinds of opportunistic infections, and even malignant tumors, will occur. Therefore, in addition to colds, AIDS patients are also prone to various types of pneumonia, tuberculosis, Pneumocystis carinii infection, cytomegalovirus infection, intestinal diseases, various types of enteritis, and general drug treatment is ineffective. Some patients are prone to malignant tumors in the advanced stage of the disease, such as common ones as Kaposi’s sarcoma and malignant lymphoma.