The weakness of the legs in the advanced stage of liver cirrhosis is related to lower limb edema, hypokalemia, poor diet and so on. 1. Lower limb edema: advanced cirrhosis can lead to hypoproteinemia due to the obvious decrease of albumin synthesis, patients can have severe lower limb edema, which can lead to the symptoms of lower limb weakness. 2. Hypokalemia: some patients with advanced cirrhosis may need to take diuretics for treatment, which accelerates the loss of potassium, and hypokalemia may occur, and hypokalemia will lead to muscle weakness. 3. Poor diet: due to gastrointestinal stagnation in advanced cirrhosis, patients may suffer from decreased appetite, and the absorption of food will be affected after eating, resulting in insufficient energy in the body, which may lead to the decrease of potassium absorption in the blood, and make the patients suffer from weakness of lower limbs. Lower limb weakness in the advanced stage of cirrhosis should be actively identified as the cause and treated under the guidance of physicians.