Sudden weakness and difficulty walking in the lower extremities may be due to hypokalemic periodic paralysis, which can be caused by a variety of factors, such as hyperthyroidism, excessive consumption of carbohydrates, exposure to cold, and mental stress. Patients with hypokalemic periodic paralysis often have prodromal symptoms such as fatigue, drowsiness, headache, etc. Patients with hypokalemic periodic paralysis may experience muscle weakness in the proximal extremities, difficulty walking, or in severe cases, generalized skeletal muscle weakness or even respiratory failure. In addition, sudden weakness of the lower extremities may also be due to cerebrovascular pathology, such as cerebral infarction patients can also appear weakness of the lower extremities, inability to move, and can be accompanied by abnormal sensation of the lower extremities, unfavorable speech, and distorted eyes and mouth symptoms. It is also possible to suffer from diseases such as Grimballi syndrome. Therefore, this condition should be further examined in the hospital to clarify the cause and provide targeted treatment.