Tetanus is often called "lockjaw" because the jaw muscles tighten, and the person cannot open his mouth.
The most common initial sign is spasms of the muscles of the jaw, or "lockjaw".

• Headache
• Jaw cramping
• Sudden, involuntary muscle tightening – often in the stomach (muscle spasms)
• Painful muscle stiffness all over the body
• Trouble swallowing
• Jerking or staring (seizures)
• Fever and sweating
• High blood pressure and fast heart rate

• Uncontrolled/involuntary muscular contraction of the vocal cords (laryngospasm)
• Break in the bone (fracture)
• Hospital-acquired infections
• Blockage of the main artery of the lung or one of its branches by a blood clot that has travelled from elsewhere in the body through the bloodstream (pulmonary embolism)
• Pneumonia, a lung infection, that develops by breathing in foreign materials (aspiration pneumonia)
• Breathing difficulty, possibly leading to death (10-20% of cases are fatal)