Pollen is the male reproductive cell of plants, and it is quite common for people to be allergic to pollen. The disease caused by pollen allergy is called hay fever, or seasonal allergic rhinitis. In the Beijing area there are two pollen high points in the year, one in the spring, caused by tree pollen, and the other in the fall, caused mainly by artemisia pollen and grass pollen. There is a strict timing of pollination for each plant species, so there is also a strict seasonality in the appearance of symptoms in patients with pollen allergy. The main clinical manifestations of hay fever are episodes of runny nose, sneezing, itchy nose, nasal congestion, itchy eyes, tearing, conjunctival bleeding, itchy ears, itchy palate, and in severe cases, cough. In addition to the obvious seasonality of hay fever, there is also an obvious geographical variation. For example, those allergic to Artemisia pollen have more severe symptoms in the north, but if they go to the south the symptoms will disappear. The diagnosis of hay fever is mainly based on clinical history, skin test and blood test. A drop of pollen allergen is applied to the flexor side of the arm. Then a special prick needle is inserted vertically through the droplet, at which point the allergen flows into the skin with the tip of the needle. If allergic, a local lump is formed surrounded by a red halo. If the skin test is positive, further blood tests are required. If the blood test is also positive, a diagnosis of pollen allergy can be made. 1.Treatment of hay fever: It is very important to avoid contact with pollen. We have accumulated a lot of experience over the years, and if you are allergic to pollen, we will give you a lot of guidance for your life. 2.Drug preventive treatment: Since pollen has a definite seasonality, we can intervene with drugs before the pollen arrives. Since everyone is allergic to different pollen with different severity, we have to make an individualized medication plan for you so that you do not commit the disease or reduce the symptoms to the least degree, and desensitization treatment is still in the research and development stage.