Limb lead low voltage is an ECG diagnostic term, which refers to the waveform height <0.5mV in the limb leads, and its causes can be divided into physiologic and pathologic causes, the former usually do not need special treatment, and the latter need active treatment of the primary disease. 1. Physiologic causes: for example, excessive obesity, the elderly, etc., can show low voltage in the limb leads during ECG examination. If the cause is clearly physiologic, no treatment is needed. 2. Pathological causes: e.g. heart failure, massive myocardial infarction, emphysema. This kind is required to be treated for the primary disease, otherwise it may be life-threatening. Patients found to have low voltage in the limb leads should go to the cardiovascular department of the hospital for further examination. Those who need it should be treated for the cause of the disease under the guidance of the doctor.