Signs and symptoms of tetanus appear anytime from a few days to several weeks after tetanus bacteria enter your body through a wound. The average incubation period is seven to 10 days.

Common signs and symptoms of tetanus include:

• Spasms and stiffness in your jaw muscles (trismus)
• Stiffness of your neck muscles
• Difficulty swallowing
• Stiffness of your abdominal muscles
• Painful body spasms lasting for several minutes, typically triggered by minor occurrences, such as a draft, loud noise, physical touch or light

Possible other signs and symptoms include:

• Fever
• Sweating
• Elevated blood pressure
• Rapid heart rate

Tetanus is caused by a toxin made by spores of bacteria, Clostridium tetani, found in soil, dust and animal feces. When the spores enter a deep flesh wound, they grow into bacteria that can produce a powerful toxin, tetanospasmin. The toxin impairs the nerves that control your muscles (motor neurons). The toxin can cause muscle stiffness and spasms — the major signs and symptoms of tetanus.

Nearly all cases of tetanus occur in people who have never been vaccinated or in adults who haven't kept up with their 10-year booster shots. You can't catch tetanus from a person who has it.

The following increase your likelihood of getting tetanus:

• Failure to get vaccinated or to keep up to date with booster shots against tetanus
• An injury that lets tetanus spores into the wound
• A foreign body, such as a nail or splinter

Tetanus cases have developed from the following:

• Puncture wounds — including from splinters, body piercings, tattoos and injection drugs
• Gunshot wounds
• Compound fractures
• Burns
• Surgical wounds
• Injection drug use
• Animal or insect bites
• Infected foot ulcers
• Dental infections
• Infected umbilical stumps in newborns born of inadequately vaccinated mothers

Once tetanus toxin has bonded to your nerve endings it is impossible to remove. Complete recovery from a tetanus infection requires new nerve endings to grow, which can take up to several months.

Complications of tetanus infection may include:

• Broken bones. The severity of spasms may cause the spine and other bones to break.
• Blockage of a lung artery (pulmonary embolism). A blood clot that has traveled from elsewhere in your body can block the main artery of the lung or one of its branches.
• Death. Severe tetanus-induced (tetanic) muscle spasms can interfere with or stop your breathing. Respiratory failure is the most common cause of death. Lack of oxygen may also induce cardiac arrest and death. Pneumonia is another cause of death.