The short answer
Lung cancer includes two main types: non-small cell lung cancer and small cell lung cancer. Smoking causes most lung cancers, but people who have never smoked can also get it. Learning the type helps guide how it is treated.
Lung cancer has two main types: non-small cell lung cancer and small cell lung cancer.
Smoking causes most lung cancers.
People who have never smoked can also develop lung cancer.
Avoiding tobacco is an important way to lower the risk of lung cancer.
Subjective: What you might experience
This section describes the symptoms and history a patient might report to their doctor.
A cough that doesn't go away or gets worse, sometimes with blood-streaked sputum.
Chest pain, often worse with deep breathing, coughing, or laughing.
Shortness of breath, wheezing, or hoarseness.
Repeated respiratory infections, fatigue, and unexplained weight loss.
Often no symptoms early
some cancers are found on low-dose CT screening.
Risk history
smoking, secondhand smoke, radon, asbestos, and other exposures.
Objective: Tests and findings
Chest imaging
chest X-ray and CT scan.
Low-dose CT screening for eligible high-risk people.
Biopsy via bronchoscopy, needle biopsy, or surgery for tissue diagnosis.
Molecular and biomarker testing (e.g., EGFR, ALK, PD-L1) on the tumor.
PET/CT and brain MRI to evaluate for spread.
Interactive anatomy guide
Explore where cancers start and how they are found, on an interactive body map.
Open the anatomy guideAssessment: Staging and prognosis
Diagnosis confirmed by biopsy; classified as non-small cell (most common) or small cell lung cancer.
Non-small cell is staged with the TNM system; small cell is often described as limited or extensive.
Molecular markers guide targeted and immune therapies in non-small cell disease.
Lung function assessed to plan treatment.
Plan: The treatment approach
Early non-small cell
surgery, sometimes with chemotherapy, radiation, or targeted/immunotherapy.
Locally advanced
chemoradiation, often followed by immunotherapy.
Advanced non-small cell
targeted therapy, immunotherapy, and/or chemotherapy based on biomarkers.
Small cell
chemotherapy with radiation, and immunotherapy in many cases.
Smoking cessation, symptom management, and clinical trials.
These are simplified, educational SOAP-style summaries showing the kinds of findings clinicians document when evaluating each cancer, based on National Cancer Institute resources. They describe typical diagnostic criteria and workups — not a real patient, and not medical advice. Real clinical notes are individualized. Always rely on your own care team. Based on National Cancer Institute educational content. Educational only — not medical advice.
Words to know
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Common questions
What are the main types of lung cancer?
The two main types of lung cancer are non-small cell lung cancer and small cell lung cancer.
What causes lung cancer?
Smoking causes most lung cancers. However, people who have never smoked can also develop lung cancer.
Can nonsmokers get lung cancer?
Yes. Although smoking causes most lung cancers, nonsmokers can also develop lung cancer.
Is there a way to screen for lung cancer?
Yes. Lung cancer screening is available. Your healthcare team can explain whether screening is right for you.
How can I lower my risk of lung cancer?
Because smoking causes most lung cancers, not smoking or quitting smoking is an important way to lower the risk. Resources such as Smokefree.gov can help people quit.
Questions to ask your doctor
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Plain-language explanation of the published sources cited on this page. AI-assisted, source-checked, not clinician-reviewed.
Sources last checked: 2026-07-21 what this meansLast updated: 2026-08-05Next planned review: 2027-07-21
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status — Source checked. This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
General education — varies by person. Answers genuinely differ between people. This page explains what commonly varies and points you to your care team for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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