There are many reasons for the patient’s legs to be weak and sore, mainly including excessive activity, herniated disc, low potassium, etc. The following is a description of the above three conditions: 1. Excessive activity: Patients who are engaged in heavy physical labor, long-term standing and other excessive leg activity can cause their legs to be weak and sore because the lactic acid produced by metabolism within the leg muscles cannot be removed in a timely manner. In addition, because the blood circulation of the lower limbs is affected by gravity, when the patient’s legs are overactive, it can cause mild blood return obstruction, and this symptom can also appear, and it can be relieved after a few minutes of rest. 2, herniated disc: when the vertebrae compress the nerve roots, it can cause the patient’s legs to be weak and sore, and it can be accompanied by abnormal sensation and limited activity. Patients can be treated by drugs and surgery, among which surgery can eradicate the symptoms of weakness and acidity in both legs. 3. low potassium: one of the main manifestations of patients with low potassium is muscle weakness, which can be seen as numbness, muscle pain, periodic paralysis, etc., mainly weakness of both lower limbs, so patients can have symptoms of weakness and acidity in both legs. In addition, patients with low potassium may also have accompanying symptoms such as weakness, arrhythmia, nausea, vomiting, etc. Patients should promptly identify and supplement potassium after diagnosis. In addition to the above-mentioned common conditions, patients with calcium deficiency, anemia, hypoglycemia, hypotension, deep vein embolism of the lower extremities and other diseases may have symptoms of weakness and acidity in both legs.