A blood glucose of 5.86 mmol/L, both fasting and 2-hour postprandial, is normal and not high. Normally fasting blood glucose ranges from 3.9-6.1 mmol/L, 2-hour postprandial blood glucose is below 7.8 mmol/L, and random blood glucose does not exceed 11.1 mmol/L. Therefore, when the blood glucose test result is 5.86 mmol/L, it is a normal blood glucose and not on the high side. Generally speaking, a transient increase in blood glucose can be caused after a high-sugar diet and under circumstances such as alcohol consumption, exercise and emotional stress, which is called physiologic hyperglycemia. Hunger, overwork and other causes may also cause blood sugar to drop and a transient hypoglycemia to occur. Hypoglycemia can trigger symptoms such as dizziness, panic, cold sweat and even fainting. If there is an absolute deficiency or relative deficiency of insulin secretion, it can also lead to elevated blood glucose. Diabetes can be diagnosed if fasting blood glucose ≥ 7.0 mmol/L or 2-hour postprandial blood glucose ≥ 11.1 mmol/L is combined with diabetes-related symptoms. If abnormal blood glucose is found, it is recommended to consult a doctor in time, follow the doctor’s instructions for examination and treatment, and follow the doctor’s instructions for regular follow-up, so as not to delay the condition.