A groundbreaking new blood test, developed by NHS England, is set to transform cancer diagnosis and treatment by detecting tumour DNA in the bloodstream. This innovative “liquid biopsy” will initially focus on lung cancer patients, offering faster, less invasive diagnosis and allowing for tailored treatment plans. But as this exciting medical advancement rolls out, experts are urging the public not to overlook the early signs of lung cancer — many of which are easy to dismiss.

The test, expected to help 15,000 patients annually, follows a successful trial involving 10,000 people with non-small cell lung cancer — the most common form of the disease. By replacing many traditional tissue biopsies, the liquid biopsy is not only quicker but more efficient in identifying genetic mutations, which can guide doctors to more precise, personalised treatments.

While technology is taking a major leap forward, early detection remains key. Knowing what symptoms to watch for could be lifesaving. Here are nine lesser-known or easily overlooked symptoms that may signal lung cancer in its early stages.

1. Shortness of Breath

Feeling winded doing activities you once managed easily? Breathlessness that persists or worsens over time should not be ignored, says Dr Rachel Orritt of Cancer Research UK.

2. Recurring Chest Infections

A chest infection that won’t clear up or keeps returning, even after treatment, may indicate something more serious is going on in the lungs.

3. Persistent Cough

A chronic cough, or a noticeable change in a long-term cough, can be an early symptom. If it doesn’t go away or worsens despite medication, it’s worth discussing with a doctor.

4. Coughing Up Blood

Even small traces of blood in your phlegm can be a warning sign and should be checked by a medical professional without delay.

5. Unexplained Fatigue

Feeling unusually tired — especially when rest doesn’t help — might be linked to underlying conditions like lung cancer, particularly if the fatigue interferes with daily life.

6. Unintentional Weight Loss

Dropping weight without trying, especially without dietary or exercise changes, is often a red flag for several types of cancer, including lung cancer.

7. Loss of Appetite

A sudden drop in appetite, or feeling full quickly, may be an early sign of systemic illness affecting the body, including cancer.

8. Unexplained or Persistent Pain

Pain in the shoulder or chest that gradually worsens or doesn’t go away can be linked to tumour growth pressing on nerves or surrounding tissues.

9. Changes in Voice

A hoarse or raspy voice that persists for more than four to six weeks — without another clear cause — could signal that something is affecting the nerves near the lungs or voice box.

What Causes Lung Cancer?

According to Dr Jenny Messenger of Nuffield Health, smoking remains the leading cause of lung cancer. However, other factors such as genetics, air pollution, exposure to asbestos or harmful chemicals, and even obesity can increase risk.

Early Diagnosis Matters

Dr Orritt urges people not to brush off persistent symptoms or attribute them to ageing or minor illnesses. “If something doesn’t feel right or isn’t going away, speak to your GP. The earlier cancer is caught, the better the chances of successful treatment.”

As medical science advances with tools like the liquid biopsy, public awareness and vigilance remain vital. Recognising the signs early — no matter how minor they seem — could save your life or the life of someone you love.