Although grapefruit is rich in nutrition and high in vitamin C, many people can't eat grapefruit, and people with hyperlipidemia and hypertension are not suitable for eating grapefruit. It is not because these people can't eat grapefruit, but when these people use some drugs to treat diseases, these drugs will find some drug reactions together with grapefruit. Because grapefruit contains a substance called coumarin, which can inhibit some metabolic enzymes in the human body, the activity of these enzymes decreases, and the human body can't decompose some drugs in time, which leads to an increase in the concentration of these drugs in the blood, which not only enhances the pharmacological effects of drugs, but also increases adverse reactions. For example, antihypertensive drugs will make antihypertensive drugs stack several times or dozens of times. There are also drugs for lowering blood fat. After eating grapefruit, the blood concentration will increase exponentially and even cause some side effects, causing dizziness and vomiting.