Taking Zuo Gui Wan for back pain may be due to the drug is not suitable for patients with this evidence type, or usual exertion as well as other diseases that lead to back pain. Zuo Gui Wan has the effect of nourishing yin and tonifying the kidneys, and is suitable for the treatment of true yin deficiency, lumbar soreness and weakness of the knees, night sweating (sweating abnormally after going to sleep, and sweating stops after waking up), and fatigue of the spirit (lack of mental energy) and dryness of the mouth which belongs to the evidence of deficiency of yin and deficiency of the kidneys. If patients with kidney yang deficiency type of lumbago take Zuo Gui Wan, it may lead to aggravation of the condition and symptoms of lumbago. Prolonged exertion, standing, bending and trauma during taking Zuo Gui Wan can lead to the appearance of lumbago, which sometimes is not caused by taking the medicine, and the cause of lumbago needs to be determined according to the specific situation. During the period of taking Zuo Gui Wan appeared back pain, can also be seen in the new onset of other diseases and lead to, such as ureteral stones lead to back pain, or usually have constipation and intestinal obstruction and the symptoms of back pain. The adverse reactions and contraindications of Zuo Gui Wan are not clear, if you feel unwell while taking it, please stop taking it and consult a doctor.