In spring, the temperature difference between day and night and the air pressure change greatly. In addition, after spring warming, pathogenic microorganisms are easy to breed, and various allergens in nature, such as flowers and dust, are also significantly increased compared with winter. These factors will stimulate the respiratory tract of the human body and produce symptoms such as cough and expectoration, which is called "spring cough". In addition, the climate in spring is dry, and the upper respiratory mucosa is vulnerable to bacterial invasion, resulting in dry cough. Fungal pneumonia, tuberculosis, non-infectious pneumonia, pulmonary embolism and other lung diseases have entered a period of high incidence. In this special period, besides keeping indoor ventilation, avoiding excessive fatigue and paying attention to personal hygiene, ensuring a scientific diet and eating more foods suitable for nourishing the lungs can also play an important preventive role. The exquisite medicine for relieving cough and nourishing yin-"Bird's nest porridge" Bird's nest has been a precious nourishing medicine since ancient times, and its efficacy of nourishing yin and moistening lung has been praised by ancient medical prescriptions and classics. "Compendium of Materia Medica" records: "Bird's nest is sweet in taste, flat in nature, nourishing lung and yin, resolving phlegm and relieving cough, and nourishing. It is a holy medicine to recuperate fatigue. All diseases can't be cured because of lung deficiency, so they can be cured. " Modern medicine also found that bird's nest is rich in minerals, active proteins, collagen and other nutrients, which can promote cell regeneration, enhance human immunity, restore vitality and delay human aging. Traditional Chinese medicine believes that bird's nest can nourish yin and moisten dryness, replenish qi and tonify the middle warmer, and treat asthenia, expectoration and asthma, hemoptysis and chronic dysentery, and is suitable for the elderly with weak constitution, malnutrition, chronic malaria, cough with excessive phlegm, chronic bronchitis, bronchiectasis, emphysema, tuberculosis, hemoptysis and vomiting blood, and stomachache. The best way to make bird's nest is to stew it on water with slow fire. "Help the bitter sea side" contains: "For dysentery, white bird's nest is two yuan, ginseng is four points, and water is ten points. Boil the soup and eat slowly. " In the Qing Dynasty, Cao Tingdong's Essay on Health Care, Volume 5, The Theory of Porridge Spectrum also recorded: "Bird's nest porridge nourishes the lungs, eliminates phlegm and relieves cough, and it is effective to cook porridge lightly." It should be reminded that bird's nest porridge is only effective if it is eaten continuously all the year round, because its nature is peaceful and its function is gradually infiltrated, not once or twice. Excerpted from the old vegetable farmer's organic vegetable network.