 In humans , a bite causes rapid and conspicuous swelling , intense pain , severe shock and local blistering . Other symptoms may include <unk> movements , defecation , <unk> , swelling of the tongue and eyelids , <unk> and unconsciousness . <unk> , bruising and <unk> may be extensive . There may be sudden <unk> , heart damage and <unk> . The blood may become <unk> with internal bleeding that may lead to <unk> and <unk> . Local tissue damage may require surgical excision and possibly <unk> . Healing may be slow and fatalities during the recovery period are not uncommon . 
