Sore throat, painful dysphagia, stiff neck, and difficulty in beginning micturition may be early evidence of muscular irritability. The dental officer may be the first to see the patient if trismus has been mistaken for some oral condition. Trismus and risus sardonicus resulting from spasm of the masseters and muscles of the face are signs of established tetanus. The contractions are aggravated by additional spasms whenever any sensory excitation occurs. Usually reflex spasms are brought on by external stimuli, such as moving the patient or striking the bed, but later they occur spontaneously at regular and increasingly frequent intervals until the height of disease is reached.
Spasms often begin with a sudden jerk.
A severe spasm may result in respiratory arrest. Spasms may last a few seconds or several minutes. When spasms occur frequently, they lead to rapid exhaustion and sometimes to death from asphyxiation. Without spasms, mortality is low. Few patients with severe spasms survive.