Carcinoid syndrome is a group of symptoms associated with carcinoid tumors. A carcinoid tumor is a rare cancer that occurs most commonly in the gastrointestinal tract or lungs. When the tumor produces too much of the hormone serotonin, it begins to exude certain chemicals into the bloodstream, causing a wide range of symptoms. Carcinoid syndrome typically occurs in individuals who have carcinoid tumors that are advanced and treatment usually depends on the severity of the condition. Treatment options for carcinoid syndrome typically involve the use of medications, or in more severe cases, surgery.



The most common signs and symptoms of carcinoid syndrome include:

  • Stomach pain
  • Chest pain
  • Red flushing of the skin
  • Diarrhea
  • Shortness of breath
  • Tiredness
  • Low blood pressure
  • Wheezing
  • Skin lesions on the face
  • Fast heart rate
  • Weight gain
  • Increased  body and facial hair



Carcinoid syndrome is caused when by a carcinoid tumor that secretes hormone serotonin or other chemicals into the bloodstream. Carcinoid tumors occur most commonly in the gastrointestinal tract (stomach, small intestine, appendix, colon and rectum) or in the lungs.When carcinoid tumors overproduce substances such as serotonin that usually flow throughout the body, the overproduction of serotonin and other hormones can cause symptoms of carcinoid syndrome (stomach pain, tiredness, shortness of breath, diarrhea and others). Carcinoid tumors often do not produce noticeable symptoms until they spread to the liver. This is because most of the blood circulation from the gastrointestinal tract must flow through the liver first before reaching other areas of the body. The liver has strong enzymes that are able to break down and neutralize any excess serotonin or other hormones produced by carcinoid tumors, preventing reaching other tissue areas. However, when carcinoid tumors spread to the liver, the substances they exude can more easily reach the bloodstream and other areas of the body to cause symptoms. This is why most individuals who experience carcinoid syndrome have an advanced cancer that has spread to the liver. What causes carcinoid tumors remains unclear.


Risk factors 

Factors associated with increased risk of developing a carcinoid tumor include the following:

  • Family history of genetic syndromes
  • Ethnic background (more common in individuals of African American descent)
  • Gender (Slightly more common in women)
  • Saturated fats
  • Smoking
  • Obesity
  • Diabetes
  • Hormone replacement therapy
  • Other medical conditions



Possible complications arising from a carcinoid tumor may include the following:

  • Carcinoid heart disease
  • Bowel obstruction
  • Low blood pressure
  • Shortness of breath
  • Confusion
  • Gastrointestinal bleeding



A few recommendations that can help prevent the occurrence of carcinoid syndrome include:

  • Maintaining a healthy diet
  • Limiting alcohol consumption
  • Limiting foods that may contain the substance tyramine (aged cheese, salted or pickled meals)
  • Treating any infections as soon as they occur
  • Avoiding stress or stressful situations