Lung Cancer – Symptoms and Causes
Overview
Lung cancer begins when cells in the lungs grow uncontrollably. The lungs, two spongy organs in the chest, are essential for breathing. This disease has the highest death rate among all cancers worldwide.
Smoking is the primary risk factor for lung cancer. Risk increases with both smoking duration and quantity. However, quitting smoking can dramatically reduce the chance of developing lung cancer, even after many years of tobacco use.
It’s important to note that lung cancer can also affect non-smokers. While less common, people who have never smoked cigarettes can still develop this condition.
Signs and Problems
Lung cancer often shows no early warning signs. Most symptoms appear when the cancer has already grown quite large.
Symptoms that affect the lungs may include:
- New, persistent cough
- Pain in the chest area
- Coughing up blood (even small amounts)
- Voice changes or hoarseness
- Trouble breathing
- Wheezing sounds when breathing
When cancer spreads beyond the lungs, you might experience:
- Pain in your bones
- Headaches that don’t go away
- Weight loss without trying
- No interest in eating
- Swelling around your face or neck
These symptoms don’t always mean you have lung cancer. However, it’s better to have them checked rather than waiting.
When to Talk to a Healthcare Provider
If you notice any worrying signs, schedule a doctor’s visit right away. This is especially important if you:
- Have a cough that won’t go away
- Notice blood when you cough
- Feel chest pain that doesn’t improve
- Experience breathing problems
Smokers should talk to their doctor about quitting methods. Your healthcare provider can suggest helpful strategies like counseling, medications, or nicotine replacement options.
Causes
Lung cancer begins when lung cells develop DNA changes. Normal cells have DNA that controls growth, multiplication, and death. Cancer cells have altered DNA that leads to rapid, uncontrolled growth.
These cells don’t die when they should, creating an excess of cells. These cells may form tumors that invade healthy tissue. Over time, cancer cells can break away and spread to other body parts, becoming metastatic cancer.
Most lung cancers result from smoking, affecting both smokers and those exposed to secondhand smoke. However, lung cancer also occurs in people who have never smoked or been around smoke, sometimes without a clear cause.
How Smoking Damages Lungs
Scientists believe smoking leads to lung cancer by harming the cells lining the lungs. Cigarette smoke contains many carcinogens (cancer-causing substances). When someone breathes in smoke, these harmful chemicals immediately start damaging lung tissue.
The body tries to repair this damage at first. But with ongoing exposure, the healthy lung cells become increasingly damaged. Over time, these cellular changes can develop into cancer.
How damage progresses:
- Initial exposure damages cells
- Body attempts repairs
- Repeated exposure causes more damage
- Cellular changes accumulate
- Cancer may eventually develop
Main Lung Cancer Types
Doctors classify lung cancer into two major types based on how the cells look under a microscope. Your treatment plan will depend on which type you have.
The two primary lung cancer types include:
| Type | Description | Prevalence |
|---|---|---|
| Small Cell Lung Cancer | Typically occurs in heavy, long-term smokers | Less common |
| Non-Small Cell Lung Cancer | Includes several subtypes | More common |
Non-small cell lung cancer includes three main subtypes:
- Squamous cell carcinoma
- Adenocarcinoma
- Large cell carcinoma
Health Risks
Tobacco Use
Smoking cigarettes greatly raises your chances of getting lung cancer. The more cigarettes you smoke daily and the longer you’ve been smoking, both increase this risk.
Being Around Others Who Smoke
Non-smokers face higher lung cancer risk when they regularly breathe in smoke from others’ cigarettes. This secondhand smoke contains harmful chemicals that damage lung tissue.
Past Chest Radiation Treatments
If you received radiation therapy to your chest area for treating another cancer, you may have a higher chance of developing lung cancer later in life.
Radon Exposure
Radon is a natural gas that forms when uranium breaks down in soil and rocks. It can seep into buildings and homes. When levels get too high and you breathe it regularly, radon increases lung cancer risk.
Harmful Workplace Substances
Working around certain chemicals and materials can raise your lung cancer risk, especially if you also smoke. These harmful substances include:
- Asbestos
- Arsenic
- Chromium
- Nickel
These materials may damage lung cells over time with repeated exposure.
Family Lung Cancer History
Having a close blood relative (parent, brother, sister, or child) with lung cancer means you might have a higher risk yourself. This could be due to shared genes or similar environmental exposures within families.
Health Concerns
Breathing Difficulties
When lung cancer grows, it can block major airways, making it hard to breathe. Tumors may also cause fluid to build up around the lungs and heart.
This fluid prevents the lungs from fully expanding when you breathe in, leading to shortness of breath. Many people find this symptom particularly distressing, but treatments can help manage it.
Bloody Cough
People with lung cancer may cough up blood (hemoptysis) when tumors damage blood vessels in the airways. This bleeding can range from small streaks of blood in mucus to more severe bleeding.
Discomfort and Soreness
As lung cancer advances, it can cause pain by spreading to the lung lining or to other body parts like bones.
Chest Fluid Collection
Lung cancer can lead to fluid buildup in the chest cavity (pleural effusion). This happens when fluid collects in the space surrounding the affected lung. This condition often causes:
- Increasing shortness of breath
- Chest discomfort
- Dry cough
Cancer Spread
Lung cancer frequently spreads (metastasizes) to other body areas, commonly the brain and bones. When cancer spreads, it can cause various symptoms depending on the affected organ:
| Location | Common Symptoms |
|---|---|
| Brain | Headaches, seizures, dizziness |
| Bones | Pain, fractures, weakness |
| Liver | Abdominal pain, yellowing skin |
| Adrenal glands | Fatigue, weight loss |
While advanced lung cancer that has spread is generally not curable, treatments can reduce symptoms and extend life.
Ways to Reduce Lung Cancer Risk
Avoid Tobacco Use
Never start smoking if you haven’t already. Talk with your children early about the dangers so they understand how to resist peer pressure. Early discussions help them develop healthy attitudes toward tobacco and make smart choices when faced with temptation.
Stay Away From Others’ Smoke
If someone in your home or workplace smokes, encourage them to quit or at least smoke outside. Avoid places where smoking is common, like certain bars, and choose smoke-free environments whenever possible.
Check Radon Levels
Test your home for radon, especially in areas known for radon problems. This invisible, odorless gas can cause lung cancer.
Hardware stores sell radon test kits, or you can buy them online. Your local public health department can provide information about testing and fixing high radon levels.
Protect Yourself at Work
Take safety precautions around workplace chemicals. Always use protective equipment like face masks when required.
Ask health professionals about additional protective measures. Remember that smoking increases the danger of workplace carcinogens.
Choose Fruits and Vegetables
Eat a diet rich in various fruits and vegetables. Getting nutrients from food is better than from supplements. Avoid large vitamin doses in pill form, as some may be harmful.
Research has shown that beta carotene supplements actually increase cancer risk in heavy smokers.
Exercise Regularly
Try to be active most days of the week. If you’re just starting an exercise routine, begin slowly and gradually increase your activity level.
Regular physical activity supports overall health and may help reduce cancer risk.
