Ischemic foci are not a medical diagnosis or a name for a disease, they are a finding on MRI and CT that represents a sign. Ischemic foci in MRI is a description of a pathologic change, and ischemic foci is actually a diagnostic term specific to MRI. Pathologically, they are small demyelinated, tiny cavities in the deep white matter of the brain that are formed due to narrowing of small blood vessels deep within the brain and long-term chronic ischemia. The etiology of ischemic foci is mostly due to atherosclerosis, long-term hypertension, hyperlipidemia, resulting in systemic atherosclerosis in the cerebral vasculature secondary changes; in the clinic is commonly found in the elderly, due to ischemic foci is a chronic process, the majority of patients do not have clear and specific symptoms. If only ischemic foci are found without other symptoms, there is no need to worry, if there is numbness of the limbs, dizziness, headache and other symptoms, regular review is needed. It is recommended that patients under the guidance of professional doctors for standardized diagnosis and treatment.