Why are my legs often weak? There are several reasons why the legs are often weak: First, hypokalemia is caused by a disease called periodic hypokalemia, which has a certain relationship with genetic factors. It is recommended to eat more potassium-rich foods and not to drink alcohol. Second, patients may have some cerebrovascular diseases, especially cerebral arteriosclerosis, intracranial artery stenosis, due to arterial stenosis will lead to transient cerebral blood supply deficiency, in terms of treatment, it is recommended to control risk factors, such as hypertension, hyperlipidemia, diabetes, etc., as far as possible to stop smoking, but also can take blood circulation, blood stasis, improve brain blood supply of Chinese medicine.