Tetanus is a life-threatening toxin-mediated neurological disease that usually begins 48 hours to 2 weeks after Clostridium tetani spores enter a wound. Classic symptoms progress in a descending pattern:

1. Lockjaw (trismus)
   Stiffness and painful spasms of the jaw muscles make it hard to open the mouth, eat, or speak; this is often the first sign .
2. Facial and neck rigidity
   Fixed “sardonic” smile (risus sardonicus) and difficulty swallowing develop as facial and pharyngeal muscles are recruited .
3. Generalized muscle spasms
   Paroxysmal, painful contractions spread to the trunk and limbs; minor stimuli such as noise, light, or touch can trigger spasms that last seconds to minutes and may cause apnea or fractures .
4. Opisthotonos
   Sustained arching of the back with flexed arms and extended legs is highly characteristic of severe disease .
5. Autonomic instability
   Episodes of hypertension, tachycardia, sweating, and fever alternate with hypotension and bradycardia; cardiac arrhythmia or arrest can occur .
6. Abdominal wall rigidity
   Continuous board-like rigidity can mimic an acute abdomen, sometimes leading to unnecessary surgery before the correct diagnosis is recognized .
7. Complication markers
   Laryngeal spasm causes asphyxia; prolonged spasms lead to rhabdomyolysis, hyperthermia, and multi-organ failure .

Patients remain fully conscious unless hypoxia supervenes. Any wound-associated stiffness or spasm mandates immediate hospital care, human tetanus immune globulin, wound debridement, and supportive ventilation .

Symptom	Early Stage	Advanced/Threatening
Jaw	Stiffness, mild trismus	Complete lockjaw
Face	Risus sardonicus	Masseter spasms
Trunk	Neck/back stiffness	Opisthotonos, fractures
Spasm trigger	Minor touch/noise	Autonomic storms
Breathing	Normal	Apnea during spasms
Vitals	Stable	Hypertension → arrest