Lung cancer is the most common type of cancer in the world, and it can have different causes. Although smoking tobacco is certainly a risk factor for developing lung cancer, it’s also possible for someone who has never smoked to develop this condition. Because no one is immune from lung cancer, it’s important to be aware of the risks and early symptoms so that you can have a conversation with your doctor about lung cancer screening.

This article describes four common types of symptoms, as well as five potential causes, of lung cancer in people who haven’t smoked.

Symptoms of Lung Cancer in People Who Don’t Smoke

The lungs have very few nerve endings, which means symptoms are harder to notice in the earlier stages. Most symptoms aren’t apparent until lung cancer has progressed to later stages, which is why most cases are diagnosed later. Here are four syndromes, or groups of symptoms, that can happen in lung cancer.

1. Lung-Specific Symptoms

In the early stages of lung cancer, you may notice milder versions of some common symptoms. These symptoms can happen when a tumor presses on structures in the lungs, such as the bronchi (airways), which can lead to:

• Shortness of breath
• A persistent cough that continues to get worse
• Chest pain
• Coughing up blood or phlegm
• Hoarseness from a tumor pressing on the trachea (main airway)
• Repeated episodes of pneumonia, or pneumonia that doesn’t go away with treatment

As the tumor continues to grow, it takes energy and resources away from the healthy cells in the body. This can make you feel tired, weak, and generally unwell.

The immune system is also trying to fight off cancer, and in the process, immune cells release proteins called cytokines. These proteins can lead to loss of appetite, weight loss, and muscle loss. This effect also makes it harder for the body to fight infections, so you may have chronic bronchitis or pneumonia that doesn’t go away.

2. Superior Vena Cava Syndrome

In some cases of lung cancer, syndromes with specific sets of symptoms can develop. These syndromes tend to affect the entire body, not just the lungs.

The syndromes develop when tumors press against larger structures in the chest or if cancer releases hormones into the body (paraneoplastic syndromes). They can also happen due to an abnormal immune response to cancer.

The superior vena cava (SVC) is a large vein that’s responsible for returning blood flow from the chest, head, neck, and arms to the heart. A tumor pressing on the SVC can restrict blood flow and cause swelling in the face, neck, chest, and arms in what’s known as SVC syndrome. Other symptoms of SVC syndrome include:

• Headaches
• Dizziness
• Discolored skin

3. Pancoast’s Tumor Symptoms and Horner’s Syndrome

Pancoast’s tumors, which occur in the topmost part of the lung, can cause specific symptoms. Pancoast’s tumors are more common in cases of non-small cell lung cancer (NSCLC) than small cell lung cancer (SCLC). Symptoms include:

• Pain in the shoulder, shoulder blade, neck, ribs, and arms
• Swelling in the upper arm
• Numbness or tingling in the hands

Pancoast’s tumors may also cause Horner’s syndrome, which results in a decreased pupil size, a drooping eyelid, and decreased sweating on the affected side of the face.

4. Paraneoplastic Syndromes

Paraneoplastic syndromes are caused by hormones or other proteins that are released from a tumor. These can happen in any type of cancer, but they’re most common in lung cancer. Paraneoplastic syndromes occur in roughly 10 percent of people with lung cancer.

The symptoms of paraneoplastic syndromes may be noticed before any lung cancer symptoms appear. If you develop symptoms of paraneoplastic syndromes, your doctor may order tests and discover lung cancer in an early and treatable stage.

Symptoms of these syndromes include:

• Slurred speech
• Knee or bone pain
• Vision problems
• Walking difficulties
• Trouble swallowing
• Dizziness or vertigo
• Seizures
• Loss of feeling in the arms and legs

What Causes Lung Cancer in People Who Don’t Smoke?

If you think you have lung cancer symptoms, it may also be helpful to understand your potential risk. Although smoking is the leading cause of lung cancer (accounting for around 80 percent of lung cancer deaths) and many other lung cancer cases can be associated with secondhand smoke, there are several other causes of lung cancer besides smoking.

For example, chemicals or irritants can cause inflammation in the lungs, eventually leading to cancer. These substances can be found in the home, in workplaces, or just in the environment. Here are five of the top causes of lung cancer in people who have never smoked.

1. Radon

Radon is a radioactive gas that forms when uranium in rocks and soil breaks down. The Environmental Protection Agency (EPA) has found that exposure to radon gas is the second leading cause of lung cancer, behind smoking.

2. Air Pollution

Exposure to exhaust and other chemical irritants in the air can lead to lung cancer. In the United States, about 1 percent to 2 percent of all lung cancer deaths may be caused by air pollution.

3. Asbestos

Asbestos is a fibrous material previously used to insulate old buildings. If inhaled, it can become trapped in the lungs and cause inflammation that leads to cancer.

4. Chemicals in the Workplace

Exposure to diesel exhaust, nickel, coal, chromium, and uranium can all increase the risk of lung cancer. These carcinogens, or cancer-causing agents, can be found in certain workplaces, such as construction sites.

5. Family History

If you have a family history of lung cancer, especially in close family members like your parents or siblings, you are at a higher risk of developing lung cancer yourself. The increased risk may be due to shared genetic mutations (changes), or it could be related to shared exposure to pollutants in the household, such as secondhand smoke.

Talk With Others Who Understand

MyLungCancerTeam is the social network for people with lung cancer and their loved ones. More than 13,000 members come together to ask questions, give advice, and share their stories with others who understand life with lung cancer.

Did you experience early symptoms of lung cancer but have no history of smoking? Share your thoughts in the comments below, or start a conversation by posting on your Activities page.