Cold is one of the common causes of dullness and sweating, which may be caused by the weather change, not paying attention to keep warm, or the recent weakening of resistance. After a cold, patients are prone to weakness of limbs, fever, sweating, runny nose and cough, and need to seek medical treatment promptly. Insufficient blood supply to the brain can also be caused by such diseases as cervical spondylosis, cerebral arteriosclerosis, cerebral vascular spasm, etc., which cause insufficient blood supply to the brain due to compression of the vertebral artery. In case of myocardial infarction, angina pectoris, arrhythmia and other cardiogenic related diseases, symptoms such as sudden weakness and cold sweat may occur due to insufficient blood supply to the brain caused by insufficient pumping of the heart. In addition, this condition may occur in cases of hypoglycemia, hypokalemia, heat stroke, and other related diseases. Therefore, if you want to know the cause of the disease, it is best to go to the hospital immediately for relevant tests to confirm the diagnosis.