5 common myths about coughs and lung cancer — and what the evidence actually says 

Lung cancer is one of the most misunderstood cancers in the UK. It’s also one of the most treatable when caught early — and one of the deadliest when it’s not. Around 50,000 people are diagnosed each year in the UK and roughly half are diagnosed at stage 4, when treatment options narrow significantly.

A big reason for those late diagnoses is what people think they know. Myths and outdated assumptions cause many of us to ignore symptoms that should be checked, or to discount our risk because we don’t fit the stereotype.

Myth 1: “Only smokers get lung cancer”

Fact: Smoking is by far the biggest risk factor for lung cancer, but it is not the only one. In the UK, around 15% of all lung cancers are diagnosed in people who have never smoked — defined clinically as having smoked fewer than 100 cigarettes in their lifetime. That equates to an estimated 6,000 UK deaths a year. If lung cancer in never-smokers were treated as a separate disease, it would be the 8th most common cancer in the UK.

The proportion of cases in never-smokers is also rising globally as smoking rates fall. UCL and Francis Crick Institute research has shown how long-term exposure to fine particulate matter (PM2.5) — found in traffic fumes, wood smoke and industrial emissions — can promote cancer-causing mutations in the lungs of people who have never smoked. Other risk factors include radon gas, asbestos, occupational carcinogens, family history and pre-existing conditions such as COPD or pulmonary fibrosis.

The takeaway: never-smokers can and do get lung cancer. Persistent symptoms deserve the same investigation regardless of whether you have ever smoked.

Myth 2: “A cough has to be severe or bloody to be a worry”

Fact: A cough does not need to sound serious to be serious. According to NHS and NICE guidance, the threshold for medical assessment of an unexplained cough is three weeks — not severity. A mild but persistent dry cough, or a long-standing cough that has subtly changed in character, can be just as significant as a dramatic one.

While coughing up blood (haemoptysis) is one of the strongest red flags and should always be assessed promptly, research suggests only around 20% of people with lung cancer experience it. That means roughly four in five patients never cough up blood — yet many wait, assuming “if it were cancer, I’d see blood.” Other warning signs to take just as seriously include unexplained breathlessness, chest or shoulder pain, recurrent chest infections, hoarseness, fatigue and unintentional weight loss.

The takeaway: persistence and change matter more than drama. A mild cough that has lasted three weeks deserves the same attention as a dramatic one.

Myth 3: “If my cough was cancer, it would show symptoms early on”

Fact: Lung cancer is notorious for being symptomatically quiet in its earliest stages. NHS England explicitly notes that “lung cancer does not usually cause noticeable symptoms until it’s spread through the lungs or into other parts of the body.” Tumours are often small and tucked away in lung tissue that has very few pain receptors, so they can grow without causing the cough, breathlessness or pain you might expect.

The numbers tell the story. According to the Office for National Statistics, fewer than 1 in 6 lung cancers in England are caught at stage 1, while around half are diagnosed at stage 4.

This is exactly why a Lung Health Check and low-dose CT screening exist — to catch cancers before symptoms appear, when they are most treatable.

The takeaway: waiting for “obvious” symptoms is one of the riskiest things you can do. Early lung cancer is usually silent.

Myth 4: “I’m too young or too healthy to have lung cancer”

Fact: Lung cancer is more common with older age — UK incidence is highest in people aged 80–84 — but it is not exclusive to older adults. UK data published in the European Journal of Cancer found that young adults aged 18–39 still account for around 0.5% of non-small cell lung cancer (NSCLC) cases. That is a small proportion, but in a country with 50,000 new lung cancer diagnoses each year, it adds up to hundreds of younger people every year.

There are two reasons this matters. First, lung cancer in younger adults is often biologically different — it tends to be adenocarcinoma, frequently driven by genetic mutations (such as EGFR or ALK) rather than by smoking, and is more responsive to modern targeted therapies when found. Second, younger and otherwise healthy patients are far more likely to present at an advanced stage because neither they nor their GPs initially suspect cancer. One UK study found that 71% of younger adults with lung cancer were diagnosed at stage III or IV, compared with around half across all age groups.

Being young or fit reduces your risk — it does not eliminate it. Symptoms in a healthy 35-year-old still warrant investigation if they have lasted more than three weeks.

The takeaway: age and fitness reduce risk but do not remove it. Don’t let “I’m too young for this” delay an assessment.

Myth 5: “A cough that comes and goes can’t be serious”

Fact: An intermittent cough can be just as significant as a constant one — particularly if the pattern has changed over weeks or months. Lung cancer-related coughs are often not continuous. They may flare for a week, settle, and return; they may be worse at night; they may sound different from your “usual” cough.

What matters clinically is change and persistence, not constancy. A study published in BJGP Open found that the single largest cause of delay in lung cancer diagnosis is patients failing to recognise their own symptoms — with researchers reporting that almost half (46.7%) of patients had delayed seeking help because they had normalised or dismissed what they were experiencing. A separate UK population study found that 38% of people could not recall any lung cancer symptoms at all.

In other words: a cough that comes and goes is one of the easiest symptoms to talk yourself out of investigating — and one of the most commonly missed. If a cough has been recurring for weeks, even with quiet spells in between, it is worth a conversation with a clinician.

The takeaway: intermittent does not mean innocent. Pattern, persistence and change are what matter.

We offer a full suite of advanced diagnostics — including Lung Health Check, low-dose CT, PET-CT, EBUS and rapid molecular diagnostics — all under one roof, with a multidisciplinary team based in the heart of Harley Street.

We accept self-pay (with fixed-price packages and 0% finance over 12 months), all major UK private medical insurers, and offer a 24/7 private GP service for anyone who needs a referral. Find out more here, if you are an international patient.

If you require a second opinion, our Lung Centre also offers these.

Disclaimer: This article is for general information and is not a substitute for personalised medical advice. Always speak to a qualified consultant about your specific diagnosis.