What are the categories of contrast reactions?

What are the categories of contrast reactions?

Three Categories: Mild Moderate Severe Mild Reactions Include Nausea and vomiting Cough Headache Itching Flushing Mild rash or hives Moderate reactions include Tachycardia or bradycardia Hypertension Hypotension Dyspnea Bronchospasm or wheezing Severe skin rash or hives Severe reactions include Laryngeal edema Convulsions Profound hypotension Arrythmias Unresponsiveness Cardiopulmonary arrest Severe reactions are considered life threatening