Low immunity can cause a variety of diseases: 1. Low immunity can lead to a series of diseases of the respiratory system, which are also the most common, such as influenza, viral colds, bronchitis, bronchitis, pneumonia, pharyngitis, tonsillitis, upper respiratory tract infections, and even lobar pneumonia and infections when immunity is low. 2. The immunity of the body can also invade the human digestive tract, leading to acute gastroenteritis, bacterial dysentery, bacterial diarrhea, infectious diarrhea, etc. 3. A series of immune disorders and connective tissue diseases, such as rheumatoid arthritis, dry syndrome, systemic lupus erythematosus, can occur when the immunity of the body is low.