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.