Symptoms include prolonged severe flushing, diarrhea, hypotension, tachycardia severe dyspnea, peripheral cyanosis and sometimes hemodynamic instability.
Other very serious conditions include:
Tahycardia: heart beating to fast
Severe Dyspnea: Shortness of breath
Peripheral Cyanosis: Lack of oxygen in the blood causing a bluish discoloration of the skin
Hemodynamic Instability: Circulatory Shock or Advanced Heart Failure