Tetanus is a severe infectious disease caused by the bacterium Clostridium tetani, which produces a potent neurotoxin. This toxin affects the central nervous system, leading to painful and sustained muscle contractions, particularly in the neck and jaw. Commonly known as 'lockjaw,' tetanus makes it difficult to open the mouth and can cause severe stiffness. The bacterium typically enters the body through puncture wounds or deep cuts contaminated with soil, dust, or animal feces. Tetanus can have fatal outcomes, especially if it affects the respiratory system.