People with ulcers and hyperacidity should not eat sour pears, lemons, bayberry, plums and other fruits with high acid content, so as to prevent the ulcer from healing. Patients with asthma should not eat fruits such as jujube, which are easy to produce phlegm and help heat, and hinder the function of spleen and stomach. Patients with constipation and hemorrhoids should not eat persimmons, hawthorn, apples and lotus seeds, because these fruits contain more tannic acid, which will stop diarrhea and aggravate the condition. Patients with anemia should not eat fruits such as oranges and persimmons with more tannic acid, because tannins are easy to combine with iron, which will hinder the body's absorption of iron. Patients with nephritis, edema and poor renal function should not eat bananas, because bananas contain more sodium salt, which will aggravate edema and increase the burden on the heart and kidneys.