The classic symptoms of tetanus include muscle stiffness, difficulty swallowing, and lockjaw (trismus). As the condition progresses, spasms can become more severe, affecting the abdomen, back, and limbs. In severe cases, spasms can interfere with breathing, posing a risk of death if not treated promptly. Symptoms typically appear between 3 days to 3 weeks after infection, depending on the proximity of the wound to the central nervous system and the bacterial load.