Weakness of the legs may be due to Kidney-Yin deficiency, because Kidney-Yin deficiency can cause weakness of the legs. But not all leg weakness is kidney yin deficiency. Kidney yin deficiency is a phenomenon caused by insufficient yin fluid in the kidneys. The main symptoms of kidney yin deficiency are five heart-heat (heat in the hearts of the hands and feet, and self-consciousness of the heart and chest), soreness of the waist and knees, weakness of the legs, night sweating (sweating abnormally after going to sleep, but sweating stops after waking up), dizziness, tinnitus, insomnia, and men’s spermatorrhea. Weakness of legs is mostly due to deficiency of kidney yin, weakening of marrow and bones, and loss of bone nourishment. In addition to kidney yin deficiency, kidney yang deficiency can also cause symptoms of leg weakness, so not all leg weakness is kidney yin deficiency. Weakness of the legs alone cannot determine the cause accurately, but also needs to be combined with the characteristics of the medical history and other test results to make an accurate judgment, it is recommended to clarify the cause of the disease under the guidance of a doctor. If you experience any discomfort, it is recommended that you seek professional medical help immediately.