Lung cancer does not always cause obvious symptoms in its early stages. When symptoms do appear, they are often similar to those caused by much more common problems, including chest infections, asthma, COPD and the after-effects of a virus.
That overlap can make it tempting to wait and see. However, a cough that does not settle, repeated chest infections, unexplained breathlessness or coughing up blood should be checked. Diagnosing lung cancer earlier can provide more treatment options and improve the chance of successful treatment.
Most people with these symptoms will not have lung cancer. The important thing is to let a healthcare professional investigate the cause rather than trying to work it out yourself.
This article provides general information and is not a substitute for individual medical advice. Call 999 for severe breathing difficulty, significant coughing of blood or other symptoms of a medical emergency.
What is lung cancer?
Lung cancer begins when abnormal cells grow uncontrollably in the lung, an airway or another nearby structure. It is different from a cancer that starts elsewhere in the body and later spreads to the lungs.
There are two main types:
- Non-small-cell lung cancer is the most common group and includes several subtypes.
- Small-cell lung cancer is less common but generally grows and spreads more quickly.
The symptoms can be similar regardless of type. They depend partly on where the tumour is, whether it narrows an airway, irritates the lining of the lung or has spread to another part of the body.
Some early lung cancers cause no symptoms and are discovered during imaging arranged for another reason or through lung cancer screening. This is why an absence of symptoms cannot completely rule out the disease in someone at higher risk.
What are the main symptoms of lung cancer?
The possible warning signs include:
- a new cough that lasts for more than three weeks;
- a long-standing cough that changes or becomes worse;
- coughing up blood or blood-stained phlegm;
- persistent shortness of breath;
- chest infections that keep returning;
- an infection that does not improve as expected;
- pain or discomfort when breathing or coughing;
- persistent chest or shoulder pain;
- unexplained weight loss or reduced appetite;
- ongoing tiredness or lack of energy.
Having one or more of these symptoms does not mean you have cancer. A persistent cough, for example, may be caused by asthma, COPD, reflux, an infection, medication or irritation from smoking. Our guide to coughs in adults explains some of these possibilities.
What matters is whether a symptom is new, persistent, unexplained or different from what is normal for you.
A persistent or changing cough
A cough is one of the best-known lung cancer symptoms, but it is also extremely common. Most short-term coughs are caused by respiratory infections and improve without serious treatment.
The NHS advises seeing a GP about a cough that has not gone away after three weeks. You should also arrange an assessment if a cough you have had for a long time changes in character, becomes more frequent or begins to produce different phlegm.
The change may be subtle. Someone who smokes or has COPD may already cough regularly and assume that a worsening cough is normal. Useful changes to notice include:
- coughing more often than before;
- a cough becoming deeper, harsher or more painful;
- producing more phlegm or phlegm of a different colour;
- developing breathlessness alongside the cough;
- being woken repeatedly by coughing;
- finding that the cough does not settle after treatment for an infection.
Keeping a brief record of when the cough began, whether it is dry or produces phlegm and what makes it worse can help at a GP appointment. Mention any blood, weight loss, chest pain, breathlessness or repeated infections.
Coughing up blood
Coughing up blood is known medically as haemoptysis. It may appear as small red streaks in phlegm, pink or rust-coloured sputum, or a larger amount of fresh blood.
Lung cancer is one possible cause, but blood can also come from a chest infection, severe coughing, bronchiectasis, a blood clot in the lung or irritation in the nose, mouth or throat. Even a small amount deserves prompt medical advice because it is not possible to identify the cause from appearance alone.
If you notice a few small spots or streaks of blood, contact your GP urgently or use NHS 111 if you cannot reach the practice.
Call 999 or go to A&E if:
- you cough up more than a few spots or streaks of blood;
- the bleeding does not stop;
- you are struggling to breathe;
- you have chest or upper-back pain;
- your heart is beating very quickly;
- you feel faint, clammy or seriously unwell.
Do not drive yourself to A&E if you are coughing up a significant amount of blood or feel seriously unwell.
Breathlessness, chest pain and repeated infections
Lung cancer can narrow or partly block an airway, affect the lining around the lung or lead to fluid collecting in the chest. These changes may cause breathlessness, discomfort or recurrent infections.
Persistent breathlessness
You may notice that ordinary activities—such as climbing stairs, walking to the shops or doing housework—make you more breathless than they used to. Breathlessness can develop gradually, so it is helpful to compare your ability with your own normal level rather than someone else’s.
There are many other possible causes, including asthma, COPD, anaemia, heart conditions, anxiety and reduced fitness. Our guide to shortness of breath and when to call 999 explains how urgency depends on the pattern and accompanying symptoms.
Chest or shoulder pain
Lung cancer may cause a persistent ache in the chest or shoulder. The pain can sometimes become worse with a deep breath, cough or laugh. It may be caused by irritation of the tissues around the lung rather than the lung tissue itself.
Chest pain has many possible explanations, ranging from strained muscles and acid reflux to heart or lung emergencies. Do not assume persistent pain is cancer, but do not ignore it either. Read our guide to chest pain and when to seek urgent help.
Chest infections that keep returning
A tumour can sometimes obstruct an airway, making infection more likely in the affected part of the lung. This may lead to repeated bronchitis or pneumonia, or an infection that improves only partly and then returns.
Further investigation may be appropriate if you repeatedly develop an infection in the same area, symptoms do not respond as expected to antibiotics, or a cough persists after the infection should have cleared.
Less common lung cancer symptoms
Not everyone develops a typical cough. Less common symptoms may occur because a tumour affects nearby nerves, blood vessels or the upper part of the lung.
A hoarse voice
A respiratory infection or heavy voice use commonly causes temporary hoarseness. Persistent hoarseness may occasionally occur when a tumour affects a nerve involved in controlling the vocal cords. See a GP if your voice remains hoarse without a clear explanation, particularly when it occurs with a cough, swallowing difficulty or weight loss.
Difficulty swallowing
A tumour or enlarged lymph node in the chest can occasionally press against the oesophagus, causing discomfort or a sensation that food is sticking. Difficulty swallowing has several possible causes, but persistent or worsening symptoms should be assessed.
Wheezing
Wheezing is a high-pitched sound produced as air moves through narrowed airways. Asthma and COPD are much more common causes, but new wheezing—especially if it seems to affect one side or does not respond to usual treatment—may need investigation.
Swelling of the face or neck
A tumour in the chest can occasionally press on a major vein that returns blood to the heart. This can cause swelling of the face, neck, upper chest or arms, sometimes with visible veins, headache or breathlessness. New, unexplained facial or neck swelling needs urgent medical assessment.
Finger clubbing
Finger clubbing means the ends of the fingers become broader or more rounded and the nails curve more than usual. It usually develops gradually and can be easy to miss.
Clubbing does not confirm cancer. It can occur with several lung, heart, liver and digestive conditions, but it should be shown to a doctor if it is new.
Changes in hormones or body chemistry
Rarely, lung cancer cells produce hormone-like substances that affect other parts of the body. This is called a paraneoplastic syndrome. It may cause symptoms such as muscle weakness, confusion, unusual thirst, constipation, nausea or changes in blood sodium or calcium.
These symptoms have many more common causes and would not usually point to lung cancer on their own.
Symptoms if lung cancer has spread
Advanced lung cancer can spread to the lymph nodes, bones, liver, brain, adrenal glands or other organs. The symptoms depend on which area is affected.
Possible symptoms include:
- persistent bone pain, often in the back, ribs or hips;
- headaches that are new or becoming worse;
- weakness or numbness in part of the body;
- problems with balance, speech or vision;
- seizures or confusion;
- yellowing of the skin or eyes;
- swollen lymph nodes, particularly above the collarbone;
- marked loss of appetite, weight or energy.
These symptoms do not necessarily mean cancer has spread. Many have unrelated causes, but they require assessment—particularly in someone already diagnosed with lung cancer.
Sudden weakness, facial drooping, difficulty speaking, a first seizure or severe confusion is an emergency. Call 999.
Who is at greater risk of lung cancer?
Smoking is the biggest preventable cause of lung cancer in the UK. Risk generally increases with the number of cigarettes smoked and the number of years someone has smoked. People who have stopped remain at higher risk than someone who has never smoked for a period of time, but the risk falls after quitting.
You should never feel that smoking means you deserve cancer or that a doctor will judge you. Healthcare professionals need an honest smoking history so they can assess symptoms and arrange suitable tests.
Lung cancer can also affect people who have never smoked. Other recognised risk factors include:
- regular exposure to other people’s tobacco smoke;
- occupational exposure to substances such as asbestos, silica, diesel exhaust or certain metals;
- exposure to high levels of radon;
- increasing age;
- a close family history of lung cancer;
- previous radiotherapy to the chest;
- some long-term lung diseases.
Having a risk factor does not mean that cancer is inevitable, and having no known risk factors does not make persistent symptoms unimportant.
People with COPD may find it especially difficult to distinguish a new symptom from their usual condition. Our guide to COPD symptoms, causes and treatment explains the typical pattern, but any lasting change should still be discussed with a GP.
When should you see a GP?
Arrange a GP appointment if you have any possible lung cancer symptom that is persistent, unexplained or different from normal. In particular, contact your practice if:
- a cough has lasted for more than three weeks;
- a long-standing cough has changed or become worse;
- you have persistent breathlessness;
- chest infections keep returning;
- you have ongoing chest or shoulder pain;
- you have unexplained appetite or weight loss;
- you feel persistently tired without a clear reason;
- your voice remains hoarse;
- your fingers have changed shape;
- you have coughed up any blood.
If you have already seen a doctor but the symptom continues, worsens or returns after treatment, arrange another appointment. It is reasonable to say clearly that you are concerned about lung cancer and ask what should happen if the first test does not explain your symptoms.
Do not delay because you are worried about wasting the doctor’s time. Most symptoms will have a non-cancerous explanation, but persistent changes still deserve investigation.
What happens when lung cancer is suspected?
A GP will ask about your symptoms, general health, smoking history and possible occupational exposures. They may listen to your chest, check your lymph nodes and measure your oxygen level. Depending on the symptoms, they may also arrange blood tests or breathing tests.
Chest X-ray
A chest X-ray is often the first imaging test. NICE recommends an urgent chest X-ray in certain people with unexplained symptoms such as cough, fatigue, breathlessness, chest pain, weight loss or appetite loss. Age, smoking history and combinations of symptoms help determine when this is appropriate.
An X-ray can show a suspicious mass, collapse of part of a lung, infection or fluid around the lung. However, it cannot provide a definite diagnosis, and some lung cancers are difficult to see on an X-ray.
If symptoms remain concerning despite a normal X-ray, return to your GP. Further assessment may still be needed.
CT scan
If an X-ray is suspicious or the clinical concern remains high, a CT scan can provide more detailed images of the lungs, lymph nodes and surrounding structures.
A suspicious scan still does not automatically mean cancer. Changes may be caused by infection, inflammation, scarring or a non-cancerous lung nodule.
Biopsy and further tests
A biopsy removes a sample of cells so they can be examined in a laboratory. Depending on where the abnormality is located, this may be collected during a bronchoscopy, through the chest wall with a needle or from a lymph node.
Other tests may include a PET-CT scan, lung-function testing and brain imaging. These help determine the type of cancer, whether it has spread and which treatments may be suitable.
The NHS guide to lung cancer diagnosis explains the main tests and what they involve.
Urgent cancer referral
If an X-ray or other findings suggest lung cancer, you may be referred through an urgent suspected cancer pathway. An urgent referral does not mean that you definitely have cancer. It means the possibility needs to be investigated promptly.
Take someone with you if you would find that helpful, and write down questions before the appointment. Ask who to contact if an expected appointment or result does not arrive.
Lung cancer screening in the UK
Screening aims to find lung cancer before symptoms appear, when treatment is more likely to be successful. It is not a replacement for contacting a GP about symptoms.
The UK National Screening Committee recommends targeted screening for people aged 55 to 74 who are considered at high risk of lung cancer. In England, the former Targeted Lung Health Check programme was renamed the NHS Lung Cancer Screening Programme in February 2025 and is being expanded nationally.
Eligible people are generally identified through their age and smoking history. An initial risk assessment determines whether a low-dose CT scan should be offered. Availability and invitations depend on the stage of rollout in the local area.
Programmes and eligibility arrangements may differ across England, Scotland, Wales and Northern Ireland. Attend if you receive an invitation, even if you feel well. If you have symptoms, contact your GP rather than waiting for a screening invitation.
You can read the current national position on the UK National Screening Committee lung cancer page.
Frequently asked questions about lung cancer symptoms
What is usually the first symptom of lung cancer?
There is no single first symptom. A persistent or changing cough is common, but some people first notice breathlessness, repeated infections, chest discomfort, weight loss or fatigue. Early lung cancer may cause no symptoms at all.
Does lung cancer always cause a cough?
No. The symptoms depend partly on the tumour’s size and location. Some lung cancers are discovered on scans before they cause any noticeable problem.
How long should a cough last before I see a GP?
The NHS recommends seeing a GP if a cough has lasted for more than three weeks. Seek advice earlier if you cough up blood, become seriously breathless, have chest pain or feel very unwell.
Can you have lung cancer without smoking?
Yes. Smoking is the largest risk factor, but people who have never smoked can develop lung cancer. Persistent symptoms should be assessed regardless of smoking history.
Does coughing up blood always mean lung cancer?
No. Infections, severe coughing, bronchiectasis and blood clots are among the other possible causes. Nevertheless, coughing up any blood requires prompt medical advice.
Can lung cancer feel like a chest infection?
It can produce similar symptoms, including cough, breathlessness, chest discomfort and tiredness. Repeated infections, an infection that does not clear as expected or symptoms that return after treatment should be reviewed.
Can a normal chest X-ray rule out lung cancer?
No test is perfect. A chest X-ray is a useful first investigation, but small or hidden tumours may not always be visible. Return to your GP if symptoms persist or worsen despite a normal result.
Is shoulder pain a symptom of lung cancer?
Persistent shoulder pain can occasionally be associated with a tumour near the top of the lung, but muscle and joint problems are far more common causes. Unexplained pain that persists—particularly alongside a cough, breathlessness, weakness in an arm or weight loss—should be assessed.
Does unexplained weight loss mean cancer?
No. Thyroid disease, digestive conditions, depression, diabetes and several other illnesses can cause unplanned weight loss. However, losing weight without trying deserves medical assessment, especially when accompanied by respiratory symptoms. See our guide to unexplained weight loss for more information.
Where can I get reliable support?
The NHS lung cancer information covers diagnosis and treatment. Cancer Research UK and the Roy Castle Lung Cancer Foundation also provide detailed information and support for patients and families.
