Leg weakness in the elderly is considered to be possibly caused by hypokalemia, anemia, cerebrovascular, and physiological decline of the musculoskeletal properties of the lower extremities. Leg weakness is clinically known as bilateral lower limb weakness, which refers to the decrease of lower limb muscle strength due to various reasons, sometimes accompanied by activity limitation. 1. Hypokalemia: Older people usually suffer from insufficient intake and excessive discharge of potassium ions, resulting in serum potassium ions below a certain level, which in turn affects the normal physiological activities of nerves and muscle cells and triggers weakness of both lower limbs. 2. Anemia: the elderly may suffer from iron deficiency anemia due to nutritional deficiencies, which reduces hemoglobin in the blood, decreases the ability of transporting oxygen, and results in hypoxia, which leads to generalized weakness, which is more obvious in the lower limbs. 3. Cerebrovascular disease: cerebral infarction is more common, the cerebrovascular of the elderly generally due to a variety of factors, resulting in vascular aging, stenosis, atherosclerosis, etc., when the cerebral blood vessels are blocked by blood clots, it can show limb weakness, or even hemiplegia, generally unilateral. 4. Physiological decline of muscles and bones of the lower limbs: as the age of the elderly continues to grow, the content of bone calcium decreases every year, resulting in bone calcium loss, so that bone density decreases. Muscle will also decay every year, lower limb muscle strength and joint stability, easy to lead to the elderly leg no strength. The causes of leg weakness in the elderly are complex, and it is recommended to consult a doctor for a clear diagnosis and treatment as prescribed by the doctor.