Lung cancer symptoms, causes and treatment: a clear, kind guide

By the KCK editorial team Medically reviewed by Dr Mohammad Muneeb Khan, MBBS, MRCP (London), MSc Clin Onc, FRCR Last reviewed 18 July 2026 9 min read

The short answer

The most common lung cancer symptoms are a cough that lasts three weeks or more, breathlessness, repeated chest infections, and coughing up blood. Most people with these signs do not have lung cancer. But if something is new, unexplained, or will not settle, it is always worth seeing your GP.

In short

Main symptoms: a persistent cough, breathlessness, coughing up blood, chest pain, tiredness, and unexplained weight loss.
Smoking is the biggest cause (around 7 in 10 UK cases), but never-smokers get lung cancer too.
Found early, the outlook can be good: most people diagnosed at the earliest stage in England survive five years or more.
The NHS is rolling out Targeted Lung Health Checks, scanning higher-risk people before symptoms appear.
General information, not medical advice. Coughing up blood or cannot breathe? Call NHS 111, or 999 in an emergency.

Around 7 in 10 lung cancers in the UK are linked to smoking, yet about 1 in 7 cases (15%) occur in people who have never smoked. Sources: Cancer Research UK and the UK LCINS research strategy.

Cancer is frightening to read about, and lung cancer especially so. We will not sugar-coat it, and we will not frighten you either. This guide explains what lung cancer is, the symptoms to notice, how it is found and treated, and the reasons for hope.

What are the symptoms of lung cancer?

The main symptoms are a cough that does not go away after three weeks, a long-standing cough that gets worse, repeated chest infections, coughing up blood, breathlessness, tiredness, and losing weight without trying. Many of these are also caused by far more common, harmless conditions.

Signs worth noticing include:

A cough lasting three weeks or more, or a change in a cough you have had for a long time
Chest infections that keep coming back
Coughing up blood, even a small amount
Feeling breathless, or wheezing, without an obvious reason
An ache or pain in the chest or shoulder
Losing your appetite or losing weight without trying
Feeling tired or low on energy, or a hoarse voice that lasts three weeks or more

Symptoms can be easy to brush off, especially if you have smoked and expect a "smoker's cough". There is no separate list of lung cancer symptoms in women versus men, but anyone noticing these changes deserves a proper check. Noticing something early is not being dramatic, it is sensible.

What is lung cancer, and what are the main types?

Lung cancer starts in the tissue of the lungs, typically in the cells lining the airways. It is one of the most common cancers in the UK, and one of the most commonly diagnosed cancers worldwide. Doctors group it into two main types, because they behave differently and are treated differently.

Non-small-cell lung cancer (NSCLC). The most common type, making up around 8 in 10 cases. It tends to grow more slowly.
Small-cell lung cancer (SCLC). Less common and usually faster growing. It is strongly linked to smoking.

Knowing the type matters because it shapes every decision that follows, from which scans you have to which treatments are likely to help. Your team will confirm the type from a small sample of cells before recommending anything.

What causes lung cancer, and who is at risk?

Smoking is the single biggest cause of lung cancer, linked to around 7 in 10 UK cases. But it is not the only cause, and lung cancer happens in people who have never smoked too, around 1 in 7 UK cases (about 15%). Risk rises with age and with exposure to certain substances.

Smoking, including cigarettes, cigars and pipes, and breathing in other people's smoke
Radon, a natural radioactive gas that can build up indoors in some areas
Air pollution, especially long-term exposure
Workplace substances such as asbestos, silica and diesel exhaust
A family history of lung cancer, and older age

Having a risk factor does not mean you will get lung cancer, and many people with lung cancer have none of the obvious ones. Risk is about odds across large groups, never a verdict on any one person.

When should I see my GP about a cough?

See your GP if you have a cough that lasts three weeks or more, a cough that changes or gets worse, breathlessness, or any chest infection that keeps coming back. If you cough up blood, even once, book an appointment. You are not wasting anyone's time by getting a persistent symptom checked.

Your GP may listen to your chest, ask about your history, and arrange a chest X-ray. Most people who see their GP with these symptoms will not have cancer. Getting checked simply rules things out, and if something does need attention, finding it sooner almost always helps.

If you are struggling to breathe or coughing up a lot of blood, contact NHS 111 for urgent advice, or call 999 in an emergency.

How is lung cancer diagnosed?

Lung cancer is normally diagnosed with a chest X-ray first, then a CT scan if needed, and then a biopsy, where a small sample of cells is taken and examined. Further scans may be used to check the size of the cancer and whether it has spread, which doctors call staging.

Chest X-ray, typically the first test your GP arranges
CT scan, a more detailed picture of the lungs
PET-CT scan, which can show whether cancer is active elsewhere
Biopsy or bronchoscopy, to take and examine a sample of cells
Molecular testing of the sample, which can reveal changes that open up targeted treatments

The NHS is also rolling out Targeted Lung Health Checks in England, inviting people aged 55 to 74 who currently smoke or used to smoke for a lung check, with a low-dose CT scan for those at higher risk. The aim is to find lung cancer earlier, before symptoms appear, when treatment works best.

What are the treatments for lung cancer?

The main treatments are surgery, radiotherapy, chemotherapy, targeted therapy and immunotherapy. Which ones your team recommends depends on the type of lung cancer, its stage, and your general health. Often, more than one treatment is used together.

Surgery removes the part of the lung with the cancer, and can aim to cure early-stage lung cancer.
Radiotherapy uses carefully targeted radiation, or as an alternative to surgery.
Chemotherapy uses medicines that travel through the body to shrink or control cancer.
Targeted therapy works against specific changes in the cancer cells, such as EGFR or ALK.
Immunotherapy helps your own immune system recognise and attack cancer cells.

Treatment for lung cancer has changed in the last decade, and targeted therapy and immunotherapy have improved the outlook for many people, including some with advanced disease. Supportive care, which manages symptoms and helps you feel as well as possible, runs alongside treatment from the start, and charities such as Macmillan offer practical and emotional help too.

What do the stages of lung cancer mean?

Stage describes how big a cancer is and how far it has spread. Non-small-cell lung cancer is usually given a number from 1 to 4, where stage 1 is small and contained and stage 4 has spread further. Stage is the single biggest factor in the outlook.

Stage	In plain English
Stage 1	Small and only in the lung. Often treatable with surgery or radiotherapy aimed at a cure.
Stage 2	Larger, or has reached nearby lymph nodes, but still contained in the chest.
Stage 3	More advanced within the chest, often needing a combination of treatments.
Stage 4	Has spread to the other lung or another part of the body. Treatment usually aims to control it and keep you well.

Small-cell lung cancer is often described more simply as limited stage (confined to one area) or extensive stage (spread more widely). Whatever the stage, your team can explain what it means for you specifically, which matters far more than the number alone.

What is the outlook, and can lung cancer be cured?

The outlook depends on the stage at diagnosis. Cancer Research UK reports that in England, most people diagnosed at the earliest stage survive five years or more, while survival is lower when it is found later. Found early, lung cancer can sometimes be cured; found later, it can often still be controlled for a long time.

It helps to remember what survival statistics are, and what they are not. They describe large groups of people diagnosed in the past, and they cannot see the newer treatments available now. Our companion guide, what lung cancer life expectancy figures really mean, unpacks this gently.

Many people live full, active lives during and after treatment, and some live with lung cancer as a long-term condition managed over years. If you take one thing from this section, let it be a fair question for your oncologist: "What do these numbers mean for me?"

How can I lower my risk of lung cancer?

The single most effective way to lower your risk is to stop smoking, and it is never too late for stopping to help. People who stop smoking even after a diagnosis tend to respond better to treatment. Reducing exposure to radon, air pollution and workplace hazards lowers risk further.

Stop smoking, with free NHS support if you would like it. Every year without smoking lowers your risk.
Avoid second-hand smoke where you can.
Check radon levels if you live in an affected area, as testing is simple.
Take up your NHS lung health check if you are invited.

Prevention is never a guarantee, and no one who develops cancer is to blame for it. But stacked together, these steps shift the odds, which is the whole idea behind our mission.

Guides like this are free, medically reviewed, and paid for by supporters, not pharma. If yours was useful, there are many ways to help.

Get involved

Common questions

What is usually the first sign of lung cancer?

There is no single first sign, but a cough that lasts three weeks or more, or a change in a long-standing cough, is one of the most common early symptoms. Breathlessness and repeated chest infections are also common. Many people have vague symptoms at first, which is exactly why a persistent change is worth checking.

Can you have lung cancer with no symptoms?

Yes. Early lung cancer often causes no symptoms at all, which is why it can be found by chance on a scan done for another reason. It is also why the NHS Targeted Lung Health Checks programme offers scans to people at higher risk before any symptoms appear.

Is a persistent cough always lung cancer?

No, and it usually is not. A lasting cough is far more often caused by common conditions such as infections, asthma, acid reflux or the after-effects of smoking. But because a persistent cough can occasionally be a sign of something more serious, it is sensible to have one that lasts three weeks or more checked by your GP.

Do you get lung cancer if you have never smoked?

Yes, though it is less common. Around 1 in 7 lung cancers in the UK (about 15%) occur in people who have never smoked. Other causes, such as radon, air pollution and asbestos, play a part, and sometimes there is no clear reason. Never-smokers deserve the same prompt checks as anyone else.

What are the symptoms of stage 4 lung cancer?

Stage 4 lung cancer has spread beyond the lung, so symptoms can include those of the original cancer plus new ones depending on where it has spread, such as bone pain, headaches or weight loss. "Stage 4" sounds final, but for a growing number of people it can be controlled for years, especially where targeted therapy or immunotherapy is an option.

How quickly does lung cancer develop?

It varies by type. Small-cell lung cancer tends to grow and spread faster than non-small-cell lung cancer. This is one reason not to delay getting a persistent symptom checked, and also why treatments are chosen to match how a particular cancer behaves.

Sources

Medically reviewed

Dr Mohammad Muneeb Khan — MBBS, MRCP (London), MSc Clinical Oncology, FRCR

Consultant clinical oncologist, NHS England. This guide is general information, not personal medical advice. Always speak to your own clinical team; in an emergency, call 999. Full profile →