Disadvantages: Bad eggs contain lead. Benefits: preserved eggs are not only delicious food, but also have certain medicinal value. Wang Shixiong's "Diet Spectrum of Living with Interest" said: "Changing eggs, which are pungent, astringent, sweet and salty, can purge heat, sober up, remove fire from the large intestine, cure diarrhea, disperse and astringe." Traditional Chinese medicine believes that egg degeneration is cold and can cure eye pain, toothache, hypertension, tinnitus and dizziness. All people can eat it: the fire is the most suitable; Children, people with spleen-yang deficiency, diarrhea due to cold and dampness, patients with cardiovascular diseases and liver and kidney diseases should eat less.