No fever but headache and general weakness, usually have the following four causes: First, the most common causes such as wind-cold type of cold, cold and wind evil invade the body in the body immunity of the low, it will cause wind-cold type of cold, when the body temperature does not rise, but accompanied by dizziness, headache, body muscle aches, weakness. Secondly, common endocrine system diseases can also include periodic hypokalemia, which can cause weakness, pallor, bradycardia, dizziness, and headache when the blood potassium is lower than 3.5mmol/L. Third, there can be cerebrovascular insufficiency, especially headache caused by insufficient blood supply to the vertebral basilar artery, accompanied by general weakness is particularly significant. Fourth, there can also be rare diseases, such as circulatory failure due to heat stroke, which can also cause headache, accompanied by generalized weakness, etc.