Syphilis may cause numbness of the feet when it develops into stage II and III. Syphilis is a chronic, multi-systemic disease caused by the syphilis spirochete, which can affect all organs of the body, resulting in a variety of signs and symptoms. Stage 1 syphilis is characterized by a hard chancre and swollen lymph nodes. As the disease progresses and syphilis enters the second stage, the infection can spread throughout the body, and it can also cause bone and joint damage, such as arthritis and bursitis, with symptoms such as swollen and painful joints and numbness in the legs and feet. After syphilis enters the third stage, it can invade the patient’s bones, heart and nervous system, which can be life-threatening in serious cases. For example, cardiovascular syphilis can be manifested as coronary artery stenosis or obstruction, aortic closure insufficiency, etc.; such as neurosyphilis, can lead to headache, mental behavioral abnormalities, cognitive function decline, as well as hemiplegia, limb coordination disorders, etc., but also can cause numbness of the lower limbs, sensory abnormalities, lightning-like pain and other abnormalities. Therefore, once the diagnosis of syphilis is confirmed, it is necessary to go to the hospital in a timely manner, and under the guidance of the doctor to carry out reasonable treatment, which can effectively alleviate the symptoms and slow down the development of the disease.