Written with men in mind. Most of this guide applies to everyone. Details specific to women — such as screening ages and risks that differ — are not covered yet; female health guides are being written.
What it is
Lung cancer starts when cells in the lungs grow out of control. Most lung cancer is caused by smoking, but people who never smoked can get it too.[1]
There are two main groups: non-small cell lung cancer, which is more common, and small cell lung cancer. Non-small cell types include adenocarcinoma, squamous cell carcinoma and large cell carcinoma.[2]
Work-up includes CT, PET-CT and brain MRI for staging, with tissue obtained by bronchoscopy, needle biopsy, endobronchial ultrasound or surgical approaches. Molecular and immunohistochemistry testing of tumour tissue guides targeted therapy and immunotherapy.[2]
See the lobes of the lungs and the branching airways in 3D.
See it in 3DHow common it is
The American Cancer Society estimates about 229,410 new cases (110,910 in men) and about 124,990 deaths (63,040 in men) in the US in 2026.[3]
Causes and risk factors
Things you can't change
Things you can change
Symptoms worth reporting to a doctor
- A cough that doesn't go away or gets worse
- Chest pain or discomfort
- Trouble breathing or wheezing
- Coughing up blood
- Hoarseness
- Losing weight or appetite without trying, or tiredness
- Trouble swallowing
Some people have no symptoms, and these can have other causes — but they're worth checking.[2]
Screening: who, when and how
USPSTF recommends a yearly low-dose CT (LDCT) scan for adults aged 50 to 80 who have a 20 pack-year smoking history and currently smoke or quit within the past 15 years (grade B, 2021).[4] A pack-year is packs per day multiplied by years smoked: one pack a day for 20 years is 20 pack-years. Screening can find cancers early but can also lead to false alarms and further tests — talk it through first.[5]
How it's diagnosed
- Imaging
- Chest X-ray and CT scans; PET-CT and brain MRI to stage.[2]
- Biopsy
- Tissue taken by bronchoscopy, a needle through the chest, or surgery, to confirm cancer.[2]
- Biomarker testing
- Lab tests on the tumour for gene and protein changes that guide treatment.[2]
- Lung function tests
- Show how well the lungs work, which matters when planning surgery.[2]
Stages in general terms
In general terms:[6]
- Localised: only in the lung.
- Regional: spread to nearby lymph nodes or structures in the chest.
- Distant: spread to the other lung or organs such as the brain, bones or liver.
An illustration, not a stage. Human Atlas never assigns a stage. Only your own tests and your care team can do that.
Types of treatment
- Surgery. Removing part or all of a lung, mainly for early cancers.[2]
- Radiation therapy. Including highly focused radiation for some early cancers.[2]
- Chemotherapy. Before or after surgery, with radiation, or for advanced cancer.[2]
- Targeted therapy and immunotherapy. Chosen using biomarker tests on the tumour.[2]
Which option fits depends on the details of each person’s situation. Your care team decides with you.
What you can do
Quit smoking — at any age
Smoking is the leading risk factor for lung cancer. Ask your clinician about support and medicines that help you quit.[1]
Ask about LDCT
If you're 50–80 with 20 pack-years and smoke or quit within 15 years, ask about yearly screening.[4]
Test your home for radon
Radon is the leading cause of lung cancer in people who never smoked.[1]
Questions to ask your doctor
- Am I eligible for lung cancer screening? How many pack-years do I have?
- What happens if my scan shows a nodule?
- What type of lung cancer is it, and has biomarker testing been done?
- What is the stage, and what are my treatment options?
- What support is there to help me quit smoking?
Myth vs. fact
Guided lesson
Plus Chapter 1 is free for everyone.
Follow this topic step by step on the 3D body.
Start chapter 1 freeRelated topics
Abdominal aortic aneurysm (AAA)
A bulge in the body's main artery that usually causes no symptoms. Men 65–75 who have ever smoked should have a one-time ultrasound.
Heart disease and heart attack
The leading cause of death for men in the US. Most of it comes from narrowed coronary arteries — and much of it can be prevented.
Understanding cancer: the basics
What cancer is, how screening differs from diagnosis, what 'stage' means, and the main types of treatment — in plain English.
Sources
- American Cancer Society. Lung Cancer Risk Factors. Checked 23 October 2026.
- National Cancer Institute. Non-Small Cell Lung Cancer Treatment (PDQ®) – Patient Version. Checked 23 October 2026.
- American Cancer Society. Key Statistics for Lung Cancer (2026 estimates). Checked 23 October 2026.
- US Preventive Services Task Force. Lung Cancer: Screening (final recommendation, March 2021). Checked 23 October 2026.
- National Cancer Institute. Lung Cancer Screening (PDQ®) – Patient Version. Checked 23 October 2026.
- National Cancer Institute. Cancer Staging. Checked 23 October 2026.
- National Cancer Institute. Lung Cancer Prevention (PDQ®) – Patient Version. Checked 23 October 2026.
The owner of this website is not a doctor. Human Atlas provides educational anatomy information and does not diagnose, stage, or treat disease. Talk to a qualified clinician about anything concerning your own health.