There are many aspects of the causes of dizziness, sweating, and lack of energy in patients all of a sudden, which should be analyzed according to the form of onset of the patient, the underlying disease, and the triggers. The first aspect, if the patient is elderly, may be caused by cerebral vascular spasm or insufficient cerebral blood supply. The patient will have dizziness with symptoms of sympathetic excitation, which is manifested as sweating, weakness and lack of energy in the limbs, which can be clarified by doing transcranial Doppler examination. The second aspect, if the patient is accompanied by muscle aches and pains and elevated body temperature, it may be caused by upper respiratory tract infection disease. In case of fever, it will lead to dizziness, lack of energy and sweating, which can be clarified by taking temperature or according to the patient’s symptoms of external sensation. The third aspect, if the patient suddenly has low blood sugar, it will be manifested as dizziness, sweating, lack of energy, panic, hand shaking these symptoms, which can be relieved by eating.