Feeling warmSwelling of the throat and tongue or tightness in throatDifficulty breathing or shortness of breathDizzinessHeadachePain or crampsNausea, vomiting, or diarrheaShockLoss of consciousnessFeeling light-headedAnxietyAbnormal heart rate (too fast or too slow)Anaphylactic shock can be caused by an allergic reaction to a drug, food, serum, ins