Lung cancer has a distinct reputation in the cancer realm: it’s the third most common type of cancer, but it accounts for the most cancer deaths in the United States, killing more people than prostate cancer, breast cancer and colon cancer—combined.

Why is lung cancer so deadly? In part, it’s because so few cases of lung cancer—just 16 percent—are diagnosed early, according to the National Foundation for Cancer Research; too often, the cancer has metastasized or spread throughout the body by the time it’s identified. Further, some types of lung cancer can withstand chemotherapy and continue to spread.  

Knowing that, it’s important to educate yourself on what lung cancer is, whether you’re at risk, signs and symptoms that could indicate lung cancer and actions you can take to try and stay healthy. In honor of Lung Cancer Awareness Month, we’ve put together a guide to lung cancer, in hopes of empowering people to better understand it, identify it and, hopefully, prevent it.

What is lung cancer?

When a person has lung cancer, cells in the lungs grow out of control, and that cancer may spread to the lymph nodes and other parts of the body. Lung cancer is divided into two main types. Non-small cell lung cancer involves cells that are larger and tend to grow more slowly; it accounts for most diagnoses (80 to 85 percent, according to the American Cancer Society). And small cell lung cancer refers to smaller cells that tend to spread faster; often, it has spread by the time it’s diagnosed.

Who is at risk of getting lung cancer?

Far and away, the leading risk factor for getting lung cancer is cigarette smoking, according to the Centers for Disease Control and Prevention (CDC); in fact, smoking is tied to up to 90 percent of lung cancer deaths.

Other risk factors for lung cancer, according to the CDC, include:

  • Second-hand smoke
  • Exposure to radon
  • Contact with/exposure to substances such as asbestos, arsenic, diesel exhaust and certain forms of silica and chromium
  • A personal or family history of lung cancer
  • Radiation therapy to the chest

What are the signs and symptoms of lung cancer? 

Unfortunately, lung cancer is one of those “sneaky” diseases that doesn’t necessarily have signs or symptoms until the cancer has advanced. And even when it has advanced, some of those symptoms can resemble other health conditions. The CDC shares these possible signs of lung cancer:

  • Coughing that won’t go away, and worsens with time
  • Chest pain
  • Shortness of breath
  • Wheezing
  • Coughing up blood
  • Feeling tired
  • Unexplained weight loss
  • Repeated bouts of pneumonia
  • Swollen or enlarged lymph nodes inside the chest

Are there any tests to detect early lung cancer?

A low-dose computed tomography (i.e. a low-dose CT scan) could catch signs of lung cancer. The U.S. Preventive Services Task Force (USPSTF) recommends this screening for people who have a history of smoking 20 packs a year or more and people who smoke now, within the past 15 years; and are between 50 and 80 years old. 

Are there actions I can take to prevent lung cancer?

The most important thing you can do to prevent lung cancer is to stop smoking (or never start), and avoid second-hand smoke as much as possible. In addition, the EPA recommends having your house tested for radon—a cancer-causing agent you can’t smell or see. And you should avoid exposure to other chemicals, such as asbestos, arsenic, diesel exhaust and certain forms of silica and chromium.

There are also healthy, everyday actions you can take to boost your immune system and rev up your heart and lungs. Those include eating a healthy, balanced diet; getting enough physical activity (the guidelines recommend 150 minutes of moderate-intensity activity and two days of muscle-strengthening activity per week); sleeping seven to eight hours a night; finding ways to relieve stress and participating in activities you enjoy (see more details these actions and more here). And, importantly, stay on top of your regular health checkups and talk to your doctor about any concerns. Detecting lung cancer early isn’t always possible, but by educating yourself, the odds are working more in your favor.