Feeling weak all the time is mostly considered to be caused by qi deficiency or qi-blood deficiency according to the basic theory of TCM identification. Qi deficiency and low function of the internal organs do not produce enough energy, so there will be a lack of energy all over the body. At the same time, qi can produce blood and blood can carry qi, so when both qi and blood are deficient, general weakness is more likely to occur. From the western medical point of view, it is necessary to exclude the possibility of anemia, blood diseases, low potassium, etc. It is best to go to the hospital for relevant examinations, and after more relevant examinations to clarify the diagnosis, treat the symptoms.