How to Spot Early Lung Cancer Symptoms

This guide is here to give you a sensible framework. What to look out for, who needs to be a bit more alert, and what usually happens next in the UK if you go to your GP.

What is lung cancer, in plain terms?

Lung cancer starts when cells in the lung begin to grow in an uncontrolled way. Over time, that can form a tumour in the lung itself or in the airways.

Early on, it may cause no symptoms at all. Or it may cause symptoms that look like everyday respiratory issues. If it is found early, it is often confined to a small area. That is when treatment is more likely to be straightforward, and in many cases, the aim is cure.

If it is found later, treatment can still be effective, but it is usually more involved. More appointments, more decisions, and more impact on day-to-day life.

Why are early symptoms often missed?

To be honest, early lung cancer does not usually announce itself with something dramatic.

A cough can be a lingering symptom of a virus. Breathlessness can be caused by getting older, being less fit, or living with asthma or COPD.

And when symptoms creep up slowly, you adapt without noticing. You take the lift instead of the stairs. You stop going for the longer walk. You clear your throat a bit more often. Nothing screams “urgent”.

The key is not severity. It is persistence, change, and pattern. If something is hanging around or feels different from your normal baseline, it is worth a proper check.

In practice, diagnosis usually starts with a GP assessment and a chest X-ray. If symptoms persist or there is any concern, the next step is often a CT scan, and sometimes further tests depending on what the imaging shows.

It’s best to find lung cancers at an early stage - long before it causes symptoms. This principle underpins our lung cancer screening and diagnostic pathway for people at higher risk, helping detect concerns early and guide patients clearly through what happens next.

Early lung cancer symptoms to watch for

None of these symptoms automatically means cancer. Most of the time, they will have a benign explanation. But if they are persistent, new, or clearly changing, they deserve attention.

A cough that does not go away, or changes

A cough lasting more than three weeks should be reviewed. It might be a new cough or a change in an existing one. People often describe it as deeper, more frequent, more irritating, or just different from their usual.

Shortness of breath

Breathlessness with routine activities can be an early sign, especially if it is new or gradually worsening. You might notice it on stairs, walking uphill, or carrying shopping. People often slow down without realising they are compensating.

Chest, back, or shoulder discomfort

This can be dull, nagging, or persistent rather than sharp. Sometimes it is hard to pin down. If discomfort sticks around and does not have an obvious explanation, it is worth discussing.

Coughing up blood

Even a small streak of blood in phlegm should be assessed promptly. There are non-cancer causes, including infection. But this is not a symptom to “watch and wait” for weeks.

Ongoing fatigue

Fatigue is common and usually not serious. But persistent tiredness that is out of proportion, or not improving with rest, is worth mentioning, particularly if it sits alongside other symptoms.

Unintended weight loss or appetite change

If you are losing weight without trying, or your appetite has dropped for several weeks, it is sensible to get checked. Again, it is not specific to lung cancer. It is just a sign that something needs looking into.

Repeated chest infections

Frequent episodes of bronchitis or pneumonia, or infections that keep returning, can sometimes suggest an underlying issue.

It is the pattern that matters. One bad winter is one thing. Repeated infections, especially in the same area of the lung, need a closer look.

Who is at higher risk?

Lung cancer can occur in people who have never smoked. But some factors do make it more likely.

• Smoking history: current and former smokers have the highest risk. The more you have smoked, and the longer you have smoked, the higher the risk. Stopping still helps, even after many years.

• Second-hand smoke exposure: ‘Passive smoking’ - long-term exposure at home or work can increase risk.

• Workplace and environmental exposures: asbestos, radon, and some industrial dusts and chemicals can contribute. Air pollution matters too, especially over the long term.

• Personal or family history: a prior cancer diagnosis or a close family history can slightly increase risk.

If you have higher-risk features, the threshold for getting persistent symptoms checked should be lower. Not because it is definitely cancer. Because it is the sensible thing to do.

When to see a GP

If symptoms persist beyond two to three weeks, or if they are worsening, it is reasonable to book in.

Early assessment allows your GP to determine whether further tests, specialist referral, or treatments such as systemic therapy or other medical interventions may be needed.

Please seek more urgent advice if you notice:

• coughing up blood

• worsening breathlessness

• persistent chest discomfort

• unexplained weight loss

• a cough that is clearly changing and not improving

And if you have been given an abnormal scan result or told something was seen on an X-ray or CT, but you do not have a clear follow-up plan, do not sit with that uncertainty.