Watermelon contains a lot of simple sugars and fructose, which is a high glycemic index fruit, and blood sugar may further increase after eating watermelon in hyperglycemic patients. Therefore, in the case of high blood sugar, it is temporarily not recommended to eat it to avoid complications. If patients want to eat watermelon very much, they can wait until their blood sugar comes down and then eat it appropriately. In case of hyperglycemia in diabetic patients, they can eat a little bit of it when their fasting blood sugar is ≤8mmol/L. It is best to eat it in between two meals, with extra meals. Also avoid eating watermelon immediately after meals, which can lead to a rise in blood sugar. In addition, the intake of watermelon needs to be offset with the main meal. After consuming watermelon, patients should pay attention to monitor blood sugar regularly to avoid a significant increase in blood sugar that was under control due to watermelon consumption. In daily life, if patients experience hypoglycemia, it is recommended to raise sugar by containing sugar cubes or supplementing with oral liquids containing sugar. Since fruits are slow to raise sugar, it is not recommended to raise sugar by eating fruits, such as watermelon and grapes, to avoid accidents.