Eventually, the victim experiences convulsions, respiratory failure, and coma, and dies due to suffocation resulting from paralysis of the muscles used for breathing. If the victim does not receive medical attention, symptoms rapidly progress to nausea, shortness of breath, confusion, and paralysis. The victim then experiences a tingling sensation in the extremities, drooping eyelids (eyelid ptosis), tunnel vision, sweating, excessive salivation, and lack of muscle control (specifically the mouth and tongue).
The initial symptom of the bite is local pain in the bite area, although not as severe as snakes with hemotoxins. Its bite delivers about 100-120 mg of venom on average, however it can deliver up to 400 mg of venom 10 to 15 mg is deadly to a human adult. Black mamba venom contains powerful, rapid-acting neurotoxins and cardiotoxins, including calciseptine.
With a LD50 of 0.25-0.32 mg/kg, the black mamba is 3 times as venomous as the Cape Cobra, 5 times as venomous as the King cobra and about 40 times as venomous as the Gaboon viper. Black mamba venom can kill a human in 20 minutes. Black mambas are among the ten most venomous snakes in the world.