Horner syndrome is not a disease exactly, it is a group of syndromes caused by a group of diseases. It is mainly due to trauma, surgery, tumor, inflammation, etc., causing sympathetic ganglion paralysis in the neck and symptoms such as ipsilateral eye sunkenness, pupil narrowing, ptosis, and little or no sweating on the affected side. The first priority is prevention, and when doing surgery, damage to the ganglion and nerves should be avoided. Secondly, treatment of the cause, such as tumor or inflammation, should be given in time to relieve the compression or eliminate the inflammation. The third is the application of nerve-nourishing drugs, supplemented by acupuncture, physical therapy and Chinese herbal medicine.