Tetanus is caused by the invasion of tetanus bacillus into the body through skin and mucous membranes. It generally grows faster in an anaerobic environment, causing specific changes in muscles, and in severe cases, can lead to body spasms and other issues. It usually invades nerves, leading to nerve damage. The incidence rate depends on the patient's health status. If the patient's immunity is low, the incidence rate can reach over 90%, and more than 90% of patients will show symptoms within two weeks of injury, potentially retaining some infectious issues. Therefore, timely handling of tetanus bacillus infections is necessary to achieve the best preventive effects. The incubation period for tetanus is usually about one week.