Generally speaking, bleeding fingers caught in car doors need tetanus injections. Bleeding fingers caught in car doors are prone to hypoxic environments, in which Clostridium tetani from outside can easily sneak into the wound and cause infection; it is recommended to treat the wound as soon as possible and then administer tetanus toxoid or antitoxin injection. Tetanus is a specific infection caused by Clostridium tetani that is often associated with trauma and can occur after various types of trauma, including car door entrapment. The bacterium is a specialized anaerobe that grows readily in environments such as small external wound openings, wounds that are filled with necrotic tissue, blood clots, or overfilled with tight fillings and local ischemia. Although the incidence of tetanus only accounts for 1% to 2% of contaminants, the disease is very aggressive and has a high mortality rate once it develops. Therefore, it is generally recommended that tetanus immunization be administered as much as possible after trauma to prevent tetanus.