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Living with Carcinoid syndrome

A set of symptoms, like diarrhea and facial flushing, caused by hormones released from a certain type of tumor.

Understanding Carcinoid syndrome

Carcinoid syndrome is a rare condition caused by hormone-like substances released from a neuroendocrine tumor, most often one in the middle part of the gut.

It usually causes more bowel movements and diarrhea, and episodes of flushing, especially of the face. Over time it can also cause scar-like (fibrotic) changes in the abdomen and in the heart valves. It can start at any time in life.

Signs & symptoms

Symptoms vary from person to person. GARD lists these among the most common:

  • Long-lasting diarrhea
  • Episodes of belly pain
  • Night sweats
  • Skin flushing and red patches
  • Carcinoid tumor in the intestine
  • Wheezing or trouble breathing

Not everyone has every symptom. GARD's list comes from the Human Phenotype Ontology.

Diagnosis

  1. Talk with your doctor

    Share the symptoms you've noticed, when they started and your family health history. Notes and photos can help.

  2. See a specialist

    Specialists who may be involved include cancer specialists and hormone specialists.

  3. Ask which tests can help

    Your care team will decide which exams and tests can confirm the diagnosis.

  4. Connect with expert centers

    Carcinoid Cancer Foundation and Neuroendocrine Tumor Research Foundation may keep lists of experts for this condition.

Care & treatment

Care team
Cancer specialists (oncologists); Hormone specialists (endocrinologists)
Expert care
Expert lists: Carcinoid Cancer Foundation, Neuroendocrine Tumor Research Foundation
Treatment
GARD doesn't list specific treatments for this condition. Your care team will tailor care to your symptoms.
Research
Clinical trials and observational studies may be options. See the research section below.

General information, not medical advice. Your care team makes the decisions.

Everyday life

Living with a rare condition is easier with support.

  • Connect with Carcinoid Cancer Foundation and other patient organizations
  • Keep notes on symptoms, changes and questions for appointments
  • Ask about patient registries that help research
  • Look into financial aid and travel resources for care visits
Bring these questions to your next doctor visit
Where is the tumor, and how can it be treated?
Which tests can show how active the syndrome is?
How can flushing and diarrhea be managed?

Quick facts

Symptoms usually startany time in life

GARD says the symptoms come from substances released by a functional neuroendocrine tumor. GARD doesn't describe what causes the tumor itself.

Endocrine

Also known as: carcinoid tumor syndrome; excessive serotonin secretion; hormonal tumor; hormone secretion by carcinoid tumor; malignant carcinoid syndrome

Patient organizations

Source: NIH GARD · Carcinoid syndromeGARD ID 5994 · GARD page updated September 2026 · Plain-language summary by Know Rare; editorial review pending. General information, not medical advice.

You are more than your diagnosis

Perspectives from people navigating life with Carcinoid syndrome.

Explore the Carcinoid syndrome blog

Explore research for Carcinoid syndrome

Explore actively recruiting Carcinoid syndrome studies with HealthSpark.

HealthSpark

Find actively recruiting studies for Carcinoid syndrome with HealthSpark. Share your city to explore research near you.

  • Recruiting studies from ClinicalTrials.gov
  • Share your city to look for research near you
  • Eligibility is confirmed by the study team

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Powered by HealthSpark, our AI chat helper · Study information from ClinicalTrials.gov · Eligibility is confirmed by the study team.

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