High blood sugar does not usually cause dizziness, but if the blood sugar is extremely high and ketosis develops, the patient can become dizzy and even comatose. Some complications of high blood sugar can also cause dizziness. Complications of high blood sugar include diseases such as eye disease, kidney disease, cerebrovascular disease, and neurological aspects. All of these complications can lead to dizziness, nausea, and vomiting. High blood glucose not only causes dizziness, but also causes diabetes, brain disease, eye disease, heart disease, etc. Therefore, high blood glucose needs to be treated promptly and needs to be lowered through treatment or diet control, which will not only reduce complications but also keep blood glucose under control. Mild elevation of blood glucose can be controlled by diet adjustment, while severe elevation of blood glucose needs to be controlled by medication. If a diabetic patient has dizziness, he or she needs to go to the hospital in time for an examination to determine the cause and then treat the problem. In addition, you need to pay more attention to diet, take glucose-lowering drugs on time, and test your blood sugar level regularly. After high blood glucose, you need to pay more attention to rest and avoid overexertion. Therefore, when you have high blood sugar, you need to carry out glucose-lowering treatment under the guidance of your doctor.