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Hormonal and Rare Conditions Carcinoid Syndrome Symptoms
Symptoms
About carcinoid syndrome

Symptoms

The symptoms of carcinoid syndrome depend on the hormone the tumour is releasing into your bloodstream1 and can occur at any time.2

The main symptoms of carcinoid syndrome are:1-4

  • Hot, red flushing of the skin (this occurs in up to 85% of patients with carcinoid syndrome4)
  • Diarrhoea
  • Wheezing

Other symptoms of carcinoid syndrome include:2,3

  • Abdominal pain
  • Palpitations (irregular heartbeat, sensation of heart pounding, rapid heartbeat)
  • Hypotension (drop in blood pressure, making you feel dizzy, sick, weak, or confused5)
  • Weight loss 

If you think you have any of these symptoms, you should consult your doctor as soon as possible because carcinoid syndrome can lead to serious, life-threatening conditions. The sooner you can begin treatment, the better.

In later stages, carcinoid syndrome can be extremely dangerous. Possible problems include:6,7

Infographic list of four possible problems related to carcinoid syndrome. Damage to the heart valves, causing symptoms of congestive heart failure. Extreme diarrhoea leading to malnutrition and dehydration. Stomach pain, fainting, and heart palpitations. Blockage of the arteries in the liver.

References

  1. Mayo Clinic. Carcinoid syndrome. Available at: https://www.mayoclinic.org/diseases-conditions/carcinoid-syndrome/symptoms-causes/syc-20370666. Last accessed April 2025.
  2. NHS Inform. Carcinoid syndrome and carcinoid tumours. Available at: https://www.nhsinform.scot/illnesses-and-conditions/cancer/cancer-types-in-adults/carcinoid-syndrome-and-carcinoid-tumours/. Last accessed April 2025.
  3. Cleveland Clinic. Carcinoid Syndrome. Available at: https://my.clevelandclinic.org/health/diseases/22103-carcinoid-syndrome. Last accessed April 2025.
  4. CRUK. Carcinoid Syndrome. Available at: https://www.cancerresearchuk.org/about-cancer/neuroendocrine-tumours-nets/about-carcinoid-syndrome. Last accessed April 2025.
  5. NHS. Low blood pressure (hypotension). Available at: https://www.nhs.uk/conditions/low-blood-pressure-hypotension. Last accessed April 2025.
  6. NORD. Carcinoid Syndrome. Available at: https://rarediseases.org/rare-diseases/carcinoid-syndrome/#symptoms. Last accessed April 2025.
  7. Rubin de Celis Ferrari AC, Glasberg J, Riechelmann RP. Carcinoid syndrome: update on the pathophysiology and treatment. Clinics (Sao Paulo). 2018;73(suppl 1):e490s. Published 2018 Aug 20.