Lung cancer symptoms: early warning signs and when to see a doctor

Why symptoms often appear late

The inside of the lungs has very few pain-sensing nerves, and the lungs have a large reserve capacity – you can breathe normally even when part of the lung is affected. As a result, a tumour can grow for months without causing problems. Symptoms usually appear when it presses on an airway, blood vessel, nerve or the chest wall, or once it has spread.

This explains why many cases of lung cancer are found at an advanced stage, and why even mild but persistent changes in your health deserve attention.

The most common symptoms

A persistent cough

A cough that has not gone away after three weeks is the most common early symptom. If you smoke, pay particular attention to any change in your usual cough – more frequent, harsher, with different phlegm or at a different time of day.

Coughing up blood

Even a small amount of blood – streaks in phlegm or rust-coloured sputum – should be checked. It is often due to infection, but it can be a sign of a tumour.

Breathlessness and wheezing

Getting short of breath doing things you used to manage easily, or a new wheeze, can be caused by a narrowed airway or fluid around the lung.

Chest or shoulder pain

Pain that gets worse when you breathe deeply, cough or laugh, or persistent shoulder or back pain, may be caused by a tumour affecting the lining of the lung or the chest wall.

Repeated chest infections

Pneumonia or bronchitis that keeps coming back in the same area, or does not fully clear with treatment, is a reason for a CT scan.

General and less common signs

• Unexplained weight loss and loss of appetite.
• Persistent tiredness that does not improve with rest.
• A hoarse voice for more than three weeks – a tumour can affect the nerve that controls the vocal cords.
• Difficulty swallowing.
• Finger clubbing – the fingertips become wider and the nails curve more.
• Swelling of the face and neck with prominent veins on the chest, caused by pressure on a large vein; this needs urgent assessment.
• Horner syndrome – a drooping eyelid, small pupil and reduced sweating on one side of the face, seen with tumours at the top of the lung.

Some lung cancers, especially small cell lung cancer, release hormone-like substances that cause so-called paraneoplastic syndromes, such as low blood sodium, muscle weakness or raised calcium levels.

Symptoms when cancer has spread

When lung cancer has spread, symptoms depend on which organ is affected:

None of these automatically means cancer, but in someone with risk factors they call for prompt investigation.

Who is at higher risk

Symptoms should be taken particularly seriously if you:

• smoke or used to smoke, especially for more than 20 years;
• are over 40 to 50 years old;
• have worked with asbestos, silica dust or other harmful substances;
• live with high radon levels or heavy air pollution;
• have close relatives with lung cancer, or have chronic obstructive pulmonary disease (COPD).

People who have never smoked can also develop lung cancer. In them, symptoms are often put down to allergies or asthma, and diagnosis can be delayed.

Preparing for your appointment

Before you see your doctor, note when the symptoms started, how they have changed, whether you have had a fever, how much weight you have lost and which medicines you have taken. Say how many years you have smoked and roughly how much, and mention any workplace exposures. If you have previous X-rays or scans, bring them – comparing with earlier images often helps the doctor decide whether a change is new.

What tests to expect

Your GP will usually examine you, listen to your chest and arrange a chest X-ray. A normal X-ray does not completely rule out a tumour, so if symptoms continue and you have risk factors, a CT scan is often recommended – see MRI and CT scans. You may also be referred to a chest specialist.

If the scan shows a suspicious area, a bronchoscopy or CT-guided biopsy follows, and if cancer is confirmed, a PET-CT and molecular testing. Current and former heavy smokers over 50 without symptoms may be eligible for low-dose CT screening – see early detection of cancer.

When to see a doctor

Make an appointment with your GP if you have:

• a cough for more than three weeks, or a change in a long-standing cough;
• breathlessness, chest pain or repeated chest infections;
• a hoarse voice for more than three weeks;
• unexplained weight loss or persistent tiredness.

See a doctor promptly if you cough up blood. Call 112 (or your local emergency number) if you cough up a large amount of blood or have sudden severe breathlessness, severe chest pain, swelling of the face and neck or sudden weakness in a limb.

If you have already been diagnosed, our guide to cancer treatment explains the next steps.

Diagnosis and treatment abroad and in Türkiye

When waiting times for a scan, bronchoscopy or specialist appointment are long, some patients from Bulgaria and elsewhere in Europe choose fast-track diagnosis or a second opinion at large accredited hospital groups in Istanbul. Check that the hospital has a thoracic surgeon, chest physician and oncologist working as one team, ask for written results and a written plan, and agree how follow-up will continue at home. New City Clinic is a health-tourism organiser that coordinates the hospital, doctor, hotel, transfers and interpreter; the choice of tests and treatment remains with the doctors.