The symptoms of low immunity are different for different people and age groups. For teenagers, low immunity may lead to delayed development, and the more prominent manifestations are poor gastrointestinal function and low secretion of sex hormones; for middle-aged people, they may be easily tired, prone to insomnia, dreaminess, and low libido; for the elderly, they may be reflected in weakness, easily infected by viruses, and prone to illness. Most people with low immunity are accompanied by neurological weakness, poor digestive system function, and easy infection of wounds. In particular, a change of living environment can easily lead to discomfort, which in severe cases may lead to diarrhea, often accompanied by various inflammatory diseases, especially pneumonia and enteritis. Daily colds are not easy to recover from and can drag on for a long time, during which they may cause other complications, and the illness can easily recur. Most of the patients have the habits of partial eating, little food, insufficient sleep time and do not like to drink water. In conclusion, low immunity is the window of many diseases, lack of resistance to viruses and bacteria, usually it is necessary to strengthen physical exercise, eat more fruits and vegetables, do not stay up late, drink and smoke. For obese people should lose weight, if it is indigestion, you can first adjust the regulation of intestines and stomach, you can also take proprietary Chinese medicine.