Symptoms of Carcinoid Syndrome


Signs and symptoms of carcinoid syndrome are due to the release of special chemicals by the carcinoid tumours. As said earlier, only about 7% of patients with carcinoid tumour do develop carcinoid syndrome.

This is because only carcinoid tumours that have metastasize (spread) to structures like the liver, lungs and heart does cause this syndrome.

Well known signs and symptoms of carcinoid syndrome include :


Over 90% of patients with carcinoid syndrome suffer with this symptom. No wonder that this is the best known symptoms of carcinoid syndrome.

Flushing is often triggered by the consumption of alcohol, cheese, chocolate, spicy foods, hot drinks, exercise, defecation, physical, sexual or psychiatric excitements.

It could occur on the face, back or limbs. It starts as a sudden redness spreading on the face to the neck or back. There is an associated feeling of been hot or warm. There may also be increased heart beat (palpitation) and nausea or vomiting.

Flushing is thought to be caused by the release of substances that increase intestinal motility and decrease absorption including bradykinins and calcitonin gene-related peptides. These agents act on the blood vessels of the skin, causing them to dilate with increased blood flow.

Commonly, flushing involves the skin of the face, abdomen, back and limbs, lasting about 3 – 5 minutes.

In severe forms, it could also be associated with obviously distended veins on the face, redness and tears pouring from the eyes. This is common in those with long standing carcinoid.

A third form of carcinoid flush is a red patch appearing on the face or back or abdomen, lasting for minutes to hours.

Finally, the forth and final, as well as most severe form of carcinoid flush is one lasting for hours, is one associated with swelling of the face, tearing, low blood pressure, difficulty with breathing, diarrhoea and racing heart. This is an emergency and requires immediate medical attention as it is potentially fatal. This type of attack is commonly seen with lung carcinoid tumours.

Flushing episodes become less and less troublesome with time for those with carcinoid syndrome over time.

You can pick from a selection of anti-redness creams from amazon here.

Abdominal Pain

Abdominal pain is a regular component of the symptoms of carcinoid syndrome. Up to 53 % of patients with carcinoid syndrome present with abdominal pain of some degree.

This could be so severe that over 40% of all patients with carcinoid syndrome need referral to see a specialist. The pain is usually in the central abdomen. It may become generalised. It is cramping in nature, continuous, without any known relieving or aggravating factor.

If there is associated bowel obstruction, the abdomen may become distended with vomiting, plus or minus constipation.

On examination of the abdomen by the attending doctor, there would be vague tenderness elicited with hyperactive bowel sounds called borborygmi. The patient may even hear theses sound

Abdominal pain as a symptom of carcinoid syndrome is due to the release of substance P, neuropeptide K, tachykinins, prostaglandins and serotonins.

Substance P is a chemical that is involved in pain modulation in the gut. It triggers the pain receptors of the gut once it is release in more than usual quantity as in carcinoid syndrome.

Prostaglandin causes the smooth muscles of the wall of the gut to go into rhythmical contraction.

Neuropeptide K, the tachykinins and serotonins are thought to be involved in the formation of spider-web-like materials that causes adhesions and fibrosis, leading to bowel obstruction .


This is another of the known symptoms of carcinoid syndrome. It occurs in every three of four patients with carcinoid syndrome. Very watery stool is passed, which may be up to 10 – 30 times in 24 hours. This leads to severe dehydration and loss of salt (electrolytes) from the body. The diarrhoea is caused by the release of prostaglandins, motilin and serotonin. It is often associated with flushing triggered bradykinins.

Valvular Heart Diseases

Valvular heart disease occurs in over half of individuals with carcinoid tumour.

The reason for this effect on the heart is not for sure known, but it is believed that the release of substances like serotonin over a long period help to damage the heart valves. This occurs as a result of endomyocardial fibrosis (formation of spider-web-like strands in the heart, holding down the heart valves) from serotonin stimulation. On the right side of the heart, it leads to carcinoid syndrome triscupid heart valve disease, and on the left side, it leads to mitral valve disease.

Evidence for this serotonin theory stems from the fact that valvular heart disease is rare with lung carcinoid tumour compared with liver carcinoids. The lungs contains high levels of monoamine oxidase which is believed to degrade serotonin produced from these tumours. Valvular heart disease as a symptom of carcinoid syndrome of the lung is thus rare.

When it does occur with lung carcinoid, a unique type of carcinoid valvular heart disease called left-sided carcinoid valvular heart disease is seen.

Liver carcinoid deposits cause left hear valvular heart disease.

The explanations for lung carcinoids rarely causing heart disease is that the mono-amine oxidase, a chemical agent that break down serotonin making it impotent, is produced by lung cells.


One of the symptoms of carcinoid syndrome is wheezing due to bronchospasm.

This is due to the release of histamine, tachykinins and bradykinins that lead to constriction of the bronchus. Severe bronchospasm has been reported in up to 20 % of patients.

They present like they are in severe acute asthmatic attack. There is usually an associated flushing and or other skin changes.

The use of steroids and salbutamol inhalers help in relieving this symptom.

Skin Lesions

Repeated flushing from released chemicals leads to permanently distended veins on the face, arm or limbs, with associated increased pigmentation or redness in white skin called telangiectasia. Telangiectasia is commonly seen in those with a skin condition rosacea. has a wide range of skin care products that could help with these skin lesions.


Arthritis is one of the symptoms of carcinoid syndrome not well understood. What is known is that patients with carcinoid syndrome suffer with arthritis than others.


A chemical called tryptophan is needed in the production of 5-HT, from which serotonin is synthesized. During carcinoid syndrome, a high amount of serotonin is produced, depleting the body’s supply of tryptophan. Tryptophan is also needed in the production of Vitamin B3 called niacin.

Deficiency of tryptophan leads to non-production of niacin. This leads to a skin condition called pellagra, especially where there is inadequate dietary compensation.

This is thus another of the skin symptoms of carcinoid syndrome. It presents as skin rashes, diarrhoea and confusion.

The skin rashes are often found on exposed areas of the body to sunshine like the face, neck or limbs.

Other Symptoms of Carcinoid Syndrome

Other symptoms of carcinoid syndrome include confusion, low blood pressure, blush coloration of the skin, body pain, tiredness, muscular pain.

Please see the following pages for more information on carciniod syndrome.

Carcinoid Syndrome




Carcinoid tumours as causes of the signs and symptoms of carcinoid syndrome


Bailey & Love’s Short Practice of Surgery. 23 rd Edition.

C. D. Knox, C. D. Anderson, L. W. Lamps, R. B. Adkins, and C. W. Pinson Long-Term Survival after Resection for Primary Hepatic Carcinoid Tumor Ann. Surg. Oncol., December 1, 2003; 10(10): 1171 - 1175.

Lung Cancer: Principles and Practice edited by Harvey I Pass, David P Carbone, John D Minna, Andrew T Turrisi, David H Johnson

General Thoracic Surgery By Thomas W Shields, Joseph Locicero, Ronald B Ponn, Valerie W Rusch

You Can Help Keep This Site Going
If you choose to, you can help keep this site free by making very little donations. Some have donated £0.20.

Your sponsorship will cover the cost of running this site and of writing the information herein.


The information presented on this site is strictly for educational purposes only. It by no means constitutes a recommendation of treatment or substitute for medical consultations.

Medical knowledge is dynamic. Whilst every care has been taken to ensure the accuracy and up-to- date-ness of the content of this site, or its owners or partners will not accept responsibility or liability of any sort for the use of information here-in in any manner.


Contact UsFree RingtonesAfrican Foods Delivered to You
UK Railways Tickets Bethelgroups Online Shop Best Mobile Phone Deals Be Debt Free
UK JobsAll About VitaminsGet Rid of Acne