Ischemic foci in the left radiocoronal area are caused by a hardening and occlusion of the small arteries in the brain, leading to local ischemia of the brain tissue. Common causes include hypertension, diabetes mellitus, smoking, and improper diet. 1. Hypertension: Increased blood pressure can lead to endothelial damage of small arteries in the brain, which can trigger atherosclerosis in the brain, thus leading to ischemic foci. 2. Diabetes mellitus: Diabetes mellitus can lead to microangiopathy and affect fat metabolism, which can easily induce obstruction of small arteries in the coronary area and ischemic foci. 3. Smoking: toxic substances in tobacco enter the bloodstream and stimulate the atherosclerosis of small arteries in the brain, and long-term smoking will cause ischemic foci. 4. Improper diet: eating greasy food for a long time will lead to the elevation of blood fat, which will easily cause the narrowing and blockage of cerebral blood vessels, thus leading to ischemic foci in the radial coronary area. When ischemic foci appear in the left radiocoronary region, it is necessary to go to the hospital in time and take treatment according to the doctor’s instructions, control blood pressure and blood sugar, quit smoking and drinking, and eat a low-salt, low-fat and low-sodium diet.