धनुर्वात हा क्लॉस्ट्रिडिअम टिटॅनो नावाच्या जीवाणूंमुळे होतो. या जीवाणूंच्या विषामुळे चेतासंस्थेवर परिणाम होऊन झटके येतात व त्यामुळे सर्वात आधी तोंडाच्या जबडय़ाचे स्नायू आखडले जातात. नंतर त्यांचा परिणाम हळूहळू शरीरभर व्हायला सुरुवात होते. धनुर्वाताचे चार प्रकार आढळतात.

Tetanus, also known as lockjaw, is a bacterial infection caused by Clostridium tetani and characterized by muscle spasms. In the most common type, the spasms begin in the jaw, and then progress to the rest of the body. Each spasm usually lasts for a few minutes. Spasms occur frequently for three to four weeks. Some spasms may be severe enough to fracture bones. Other symptoms of tetanus may include fever, sweating, headache, trouble swallowing, high blood pressure, and a fast heart rate. Onset of symptoms is typically 3 to 21 days following infection. Recovery may take months; about 10% of cases prove to be fatal.