The flu is also called a cold, and if it is severe and widespread, it is called an influenza. Influenza is a common disease in winter. To prevent colds, the most fundamental one is to strengthen exercise and enhance physical fitness. In addition, it is necessary to prevent the attack of “external evil”. Therefore, insist on washing your face and nose with cold water to enhance the adaptability of the nasal mucosa to cold air. You can also use your fingers to rub the Yingxiang point next to the calculation for 1 to 3 minutes, or use two index fingers to rub both sides of the bridge of the nose to make it hot and promote nasal blood circulation and mucus secretion to enhance its ability to resist disease. In recent years, scientists have shown that colds are an important route of transmission through hand-to-hand contact. This is because cold viruses can survive on handkerchiefs for 1 hour and on hands for 2 hours. When people with colds wipe their noses, they transfer the live virus to their hands, and then contaminate the places they touch, such as shaking hands with others, pulling door handles, holding telephone microphones, and then transmitting the virus to healthy people. Therefore, wash your hands often with soap and do not touch your nose or eyes with your hands before washing them. If you are weak and often catch a cold, you can use the Chinese herbal medicine Astragalus 30 grams, 15 grams of wind, 15 grams of Atractylodes Macrocephalae, research into coarse powder, boiling water, when the tea is often served, 1 to 3 months for a course of treatment, this therapy to prevent and treat colds with excellent results. In addition, the living room should be “open”, so that direct sunlight, air circulation, you can also often use salt water gargle, gargle throat. In the season of cold and flu, when you go to and from public places, you can bring the same salty dried fruits on your body, such as salted olives, salted plums, etc. Once you go out, you can immediately take one in your mouth, so that there is always a little bit of salty taste in your mouth, which can play an antiseptic role.