What Is Lung Cancer?
A plain-language overview of lung cancer, its two main types, and its main cause, based on National Cancer Institute resources.
Source: National Cancer Institute · Verified 2026-07-02
5 min readBeginnerUpdated 2026-07-02
The 30-second version
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.
Key takeaways
- 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.
- Lung cancer screening is available and can look for cancer before symptoms appear.
Choose how you want to understand this
The full explanation.
The simple version
Lung cancer is cancer that starts in the lungs. It includes two main types: non-small cell lung cancer and small cell lung cancer.
Smoking causes most lung cancers. But it is important to know that people who have never smoked can also develop lung cancer.
In short: lung cancer comes in two main types, and smoking is its leading cause.
The two main types
Lung cancer includes two main types:
- Non-small cell lung cancer
- Small cell lung cancer
Learning which type is involved is a useful step in understanding a lung cancer.
What causes it
Smoking causes most lung cancers. Tobacco smoke is the main cause. Because of this, not smoking or quitting smoking is one of the most important ways to lower the risk of lung cancer. Resources such as Smokefree.gov can help people who want to quit.
Nonsmokers can also develop lung cancer. Having lung cancer does not mean a person must have smoked.
In short: most lung cancers are caused by smoking, but the disease can happen in people who never smoked.
Finding lung cancer early
Lung cancer screening is available. Screening means checking for cancer before a person has any symptoms, when it may be easier to treat. Your healthcare team can explain whether screening is right for you.
Everyone's situation is different. Your care team is the best source of information about your own risk, screening, and any next steps.
Watch instead
Animated lessons are in production. Here’s the planned video slate for this topic — each one will be based on the same NCI-sourced explanation you’re reading.
What Is Lung Cancer: the quick overview
A one-breath explanation you can watch before an appointment.
Coming soonWhat Is Lung Cancer, explained simply
The core ideas with friendly animation and plain language.
Coming soonUnderstanding what is lung cancer — full lesson
A deeper walkthrough covering the key takeaways and common questions.
Coming soonVideo transcriptâ–¾
A full, readable transcript will appear here when the video is published — so the lesson is accessible whether you prefer to watch, listen, or read. For now, the article above is the complete text version.
Suggested animation storyboardâ–¾
- 1Open on a calm title card: "What Is Lung Cancer?" with the Cancer Explained mark.
- 2Narrator reads the 30-second summary while a soft animated diagram builds on screen: "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."
- 3Scene 2: illustrate the idea — "Lung cancer has two main types: non-small cell lung cancer and small cell lung cancer."
- 4Scene 3: illustrate the idea — "Smoking causes most lung cancers."
- 5Scene 4: illustrate the idea — "People who have never smoked can also develop lung cancer."
- 6Close on a reminder card: this is educational only; talk with your healthcare team, and a link to the NCI source.
Words to know
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Quick knowledge check
According to this article, what are the two main types of lung cancer?
Frequently asked questions
â–¸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.
â–¸What causes lung cancer?
Smoking causes most lung cancers. However, people who have never smoked can also develop lung cancer.
â–¸Can nonsmokers get lung cancer?
Yes. Although smoking causes most lung cancers, nonsmokers can also develop lung cancer.
â–¸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.
â–¸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.
Test your understanding
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Review key terms
Study 8 flashcards built from this topic’s key terms and common questions — flip each card to reveal a plain-language explanation.
Questions to ask your healthcare team
Consider bringing these questions to your next appointment.
- Which type of lung cancer do I have?
- What tests do I need to learn more about it?
- Am I a candidate for lung cancer screening?
- What can I do to lower my risk or my family's risk?
- What are my general treatment options?
- Where can I find help to quit smoking?
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