Presents as: Hyperrelxia, tremors, myoclonus, anxiety, restlessness, insomnia, diaphoresis, mydriasis, tachycardia, agitation, HTN, hyperthermia, hyperactive bowel sounds, diarrhea, n/v. Considered severe when we see Rigidity, respiratory failure, tonic-clonic seizure, coma, delirium, confusion, sever hyperthermia, and dynamic blood pressure