Symptoms of lung NETs

Up to half of people with lung neuroendocrine tumours (NETs) do not have any symptoms at diagnosis. Doctors often diagnose a lung NET when doing tests for something else.

When you do have symptoms, they can be caused by the cancer itself or by hormones made by the cancer.

These symptoms could be due to a lung NET but can also be caused by other medical conditions. It’s important to get them checked by your doctor.

Symptoms caused by the cancer itself

Symptoms might include:

A cough that won’t go away

You might have a cough most of the time. It might be worse at different times of the day. 

Coughing up blood

This might be small amounts of blood. You might be coughing up rust coloured phlegm (sputum). Or your sputum might have flecks of red in it. 

It is more unusual to cough up larger amounts of blood. See your doctor straight away if this happens. Coughing up blood is called haemoptysis.

Being short of breath

You might get out of breath doing the things you used to do. Doctors call this dyspnoea.

An ache or pain in the chest

You might have pain in your chest or shoulder. It could be a dull ache or a sharper pain.

Ongoing chest infections

You might have chest infections most of the time. Or you might have a chest infection that doesn’t get better with treatment.

Feeling tired (fatigue)

You might feel very tired a lot of the time.

Losing weight

You might lose a lot of weight quickly when you are not dieting.

Symptoms caused by hormones

Some types of lung NETs make hormones that go into the bloodstream. Doctors call these functioning tumours. These hormones can cause symptoms that don’t seem related to the cancer. The symptoms might include:

Flushing of the skin

The skin of your face, neck and chest may look red (flushed).


Diarrhoea means having more than 3 watery poos (stools) in a 24 hour period. You might also have diarrhoea at night and problems controlling your bowels (incontinence).


Wheezing is a whistling sound when you breathe.

Fast heartbeat

You may feel that your heart is beating very quickly. This can make you feel dizzy, breathless and tired.

Doctors call this collection of symptoms carcinoid syndrome. It is more likely to happen if the lung NET has spread to other parts of the body, especially the liver.

When to see your doctor

You should see your doctor if you have any of these symptoms.
Last reviewed: 
25 Mar 2021
Next review due: 
25 Mar 2024
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  • The information on this page is based on literature searches and specialist checking. We used many references and there are too many to list here. Please contact with details of the particular issue you are interested in if you need additional references for this information

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