Allergy literally means that the body’s immune system reacts with excessive sensitivity to foreign substances. It is clear from this that it involves both internal and external factors, namely intrinsic allergies and external allergens. Intrinsic allergy is congenital and is determined by genetic predisposition. According to data analysis, if one parent has allergies, about 30% of their children will also have allergies; if both parents are allergic, the chances of their children having allergies are more than 50%. External allergens in infancy and early childhood are mainly food (such as milk, eggs, citrus in fruits, seafood, nuts, especially peanuts, chocolate, etc.), and other dust mites, pollen allergies, etc. The World Health Organization has designated July 8 each year as “World Allergy Day. The answer is yes. Allergies can be prevented or delayed. It can be divided into two aspects: controlling the environment and improving the inner constitution. 1. Control the humidity of the environment. A humid environment is easy for bacteria to grow, so 50% of the humidity is appropriate. 2, reduce the dust in the bedroom indoor environment to keep clean, wipe with a wet cloth, diligently change the children with sheets, covers, pillowcases and other supplies. 3, avoid contact with irritants perfume, insecticides and other volatile substances to avoid using as much as possible. Indoor use of high-performance air filters can purify the air. Avoid going to places where flowers are blooming, especially do not choose to travel in windy weather. 4, diet and health care call for mothers to breastfeed, breastfeeding can significantly reduce the allergy generation. Breastfeeding is best to adhere to until six months. Generally babies add complementary foods around four months, allergic babies can only be added after six months. If the absorption of the intestines is still unstable at six months old and prone to vomiting, the time to add complementary foods should be extended. In addition, infants and young children’s diet to light is good, seasoning and coloring as much as possible to reduce. 5, moderate exercise infancy sleep should not be covered too tightly, a little older children can be appropriate to increase the amount of outdoor exercise. Fortunately, as people age, their bodies change and their immune systems mature, most people’s allergy symptoms will improve. Young parents, please keep an eye on your children and do your best to reduce the occurrence of allergies.