Not long ago, a middle-aged female patient in the outpatient clinic, the main statement of dizziness and fatigue in the past month, had consulted the Department of Neurology, blood pressure, head CT, vertebral basilar artery Doppler ultrasound examination did not show any abnormality, and taking drugs to improve the cerebral blood supply did not have a significant effect. Self-measurement of blood glucose was basically at normal or slightly higher levels. Recent glycated hemoglobin is normal. Detailed understanding of dizziness and fatigue in the afternoon and evening after eating three hours more prominent, currently taking Repaglinide 0.5 days three times, metformin 0.5 days three times. Consider the possibility of hypoglycemia. The patient was given dynamic glucose monitoring, and the results suggested that the blood glucose was low in the afternoon and evening after three hours of meals, between 3.7 and 4.9. The treatment program was adjusted, and Repaglinide was discontinued, and the dizziness and fatigue disappeared in the follow-up. Inspiration: In the clinic, hypoglycemia in some patients is relatively insidious, not with typical palpitations, sweating, easy to starve and other symptoms as the prominent manifestations, and it is often difficult to monitor blood glucose to capture the low blood glucose, and timely dynamic blood glucose monitoring can be timely detection of the cause of the disease.