Apple is rich in sugars, acids, aromatic alcohols and pectin, and contains vitamins B and C, calcium, phosphorus, potassium, iron and other nutrients. As early as the Tang Dynasty, the medicinal use of apples was recorded. Apples not only benefit the heart, strengthen the spleen, but also produce fluid to quench thirst. They also have the functions of "moistening the lungs and pleasing the heart, producing fluid to stimulate appetite and sober up". Apples are sweet and sour, and cool. Modern medical research has proved that eating more apples in patients with severe edema is beneficial to supplement potassium and reduce side effects. Eating more apples during pregnancy can not only supplement vitamins and other nutrients, but also adjust the balance of water saving, salt and electrolyte to prevent acidosis caused by frequent vomiting. Apples can also be used as a whole intestine antidiarrheal agent. In Compendium of Materia Medica, there is a saying that "if the diarrhea persists, people who are half-cooked can eat it 10, with 2 liters of water and decoction 1 liter". There are still folk methods to treat chronic diarrhea, neurocolitis and intestinal tuberculosis with apples. Germans also use "Morrow Apple Therapy" to treat enteritis. In addition, eating an apple on an empty stomach every morning and evening can treat dry stool. Eating apples after meals has a certain effect on nausea and indigestion; Patients with hypertension insist on eating apples three times a day, each time1-2, which can get antihypertensive effect.