After stepping on the nail deep wound can form an anaerobic environment, and Clostridium tetani belongs to anaerobic bacteria, so if the foot stepped on the nail after the occurrence of lacerations, may cause tetanus clostridium infection and reproduction, resulting in the occurrence of tetanus. Generally, the incubation period of tetanus is 5-14 days, and the shorter the onset time, the worse the prognosis. 1, systemic symptoms: usually may appear weakness, dizziness, headache, irritability and other symptoms, can appear in the 12-24 hours of the onset; 2, local symptoms: in the local area of the foot on the nail may appear muscle tension, tearing pain, or jaw stiffness, swallowing difficulties and muscle tension in the neck or Soreness and other symptoms. If the prodromal symptoms are not taken seriously and treated in a timely manner, there is a risk that the condition will gradually become more severe as it progresses, with a characteristic bitter smile on the face and a twisted, arch-shaped trunk caused by simultaneous contraction of the back and abdominal muscles. Any slight stimulus, such as sound, light, vibration, drinking water, injection, etc., may trigger strong muscle spasms or even respiratory distress or cessation of breathing. Usually, in case of nail puncture, especially if the nail is rusted or contaminated, and if the wound is deep, one should actively seek medical attention and prevent tetanus by standardizing the tetanus vaccination under the guidance and advice of a doctor.