Carcinoid syndrome is a mix of syndromes generated by hormones and other chemical substances discharged by the tumors toward the bloodstream. These tumors mostly appear in the gastrointestinal tract or lungs. Around ten percent of the people with carcinoid tumors will develop carcinoid syndrome. The manifestation of the carcinoid syndrome differs depending on which hormones are discharged by the tumors. Serotonin, histamine, bradykinin, and chromogranin are the prevalent hormones released.
The primary nature of carcinoid syndrome consists of flushing, diarrhea, recurring abdominal pain, cough (wheezing), low blood pressure and heart palpitations.