Human fatalities as a result of bites from this species are rare due to the fact that this species does not often cross paths with humans, but bites have occurred and the majority of the recorded bites have been fatal. The three species of green mambas, including the western green mamba, have venom toxicities that are similar to and comparable to many species of cobras, but green mamba bites often present with more severe and life-threatening symptoms in a shorter period of time. Mortality rates are also higher among green mamba bite victims than with cobra bite victims. Although bites by "Dendroaspis viridis" are not well documented and the rate of bites, envenoming and fatality is not well known, it appears that bites attributed to this species produce more severe envenomation than bites caused by "Dendroaspis angusticeps" (eastern green mamba), but far less severe than bites caused by "Dendroaspis polylepis" (black mamba). When bitten, symptoms rapidly begin to manifest, usually within the first 15 minutes or less. The extraordinary speed with which the venom spreads through tissue and produces rapid manifestations of life-threatening symptoms is unique to mambas. Common symptoms of a bite from a western green mamba include local pain and swelling, although uncommon, local necrosis can be moderate, ataxia, headache, drowsiness, difficulty breathing, vertigo, hypotension (low blood pressure), diarrhea, dizziness, and paralysis. Left untreated, new and more severe symptoms rapidly progress. All symptoms worsen and the victim eventually dies due to suffocation resulting from paralysis of the respiratory muscles. Bites with envenomation can be rapidly fatal, which can be possible in 30 minutes.