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Lung cancer

Overview and symptoms of lung cancer

Lung cancer is the 3rd most common cancer in both women and men.


The disease tends to be hard to find in the early stages. Lung cancer is the number one cause of cancer-related deaths — more than colon, breast, and prostate cancers combined.

However, there are different types of lung cancer, which vary in prognosis (expected recovery).

At Dignity Health, we provide compassionate lung cancer treatment with sensitivity to your mental, physical, and spiritual needs. Find a Doctor near you using our online tool.


In the early stages, lung cancer doesn’t typically cause any symptoms. Cancerous tumors can grow in the lungs without causing pain or discomfort. Over time, these tumors may grow and spread, eventually leading to symptoms.


When symptoms of lung cancer do develop, they may include:

  • Coughing up blood or bloody, rust-colored mucus
  • Chest pain that gets worse with deep breathing, laughing, or coughing
  • Hoarseness
  • A new cough that does not go away, or a cough that worsens over time
  • Changes in a chronic cough or “smoker’s cough”
  • Shortness of breath or wheezing
  • Tiredness or weakness
  • Chronic headaches
  • Unexplained weight loss and loss of appetite

If you notice any of these continuing symptoms, contact your doctor. By the time many people notice symptoms, lung cancer has spread too much to be cured. The earlier you can be diagnosed, the better the chances that treatment will be successful.


The underlying mechanisms that cause cancer are not fully understood. Cancers result from cell mutations (changes), which can build up and turn into tumors. These cells may then spread throughout the body. A few things can cause these mutations, but one likely culprit is tissue damage from inhaling carcinogens and irritants.

The most common cause of lung cancer is smoking.


Smoking causes damage to the lining of the lungs. Initially, the body can repair this damage, but over time the lining will become increasingly damaged, increasing the likelihood of cancerous growth.

While long-term smoking carries the highest risk, even an occasional smoking habit increases risk. Being exposed to secondhand smoke can also lead to lung cancer.


When you are diagnosed with lung cancer, your doctor will examine the tissue through a biopsy (sample). The specific type of lung cancer is based on the type of cell, and that will determine the optimal treatment path for you.

There are three main types of lung cancer:

  • Non-small cell lung cancer (NSCLC) is the most common. About 85 percent of lung cancers are this type. It tends to grow and spread slowly. There are three subtypes of NSCLC: adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.
  • Small cell lung cancer tends to grow and spread quickly. There are two subtypes: oat cell (the most common) and combined small cell carcinoma.
  • Carcinoid is a less common type of lung cancer, which grows very slowly.

Risk factors

Smoking is the number one risk factor for developing lung cancer. In fact, smoking causes 9 out of 10 lung cancer cases. Smoking includes cigarettes, pipes, and cigars. Your risk grows the longer you smoke and with every increasing number of cigarettes you smoke per day (or the amount of tobacco you use). The good news is that quitting decreases your risk, regardless of your age.


Other factors that make you more likely to develop lung cancer are:

  • Family history of lung cancer. Having an immediate family member such as a parent, aunt/uncle, sibling, or child diagnosed with lung cancer may mean that you are at a higher risk of developing the disease.
  • Exposure to secondhand smoke. Even if you do not smoke yourself, being around those who smoke increases your exposure to toxins that damage the lining of the lungs.
  • Exposure to radiation. Radiation exposure is the second-most common cause of lung cancer after smoking. While radiation exposure can result from radiation therapy from cancer treatment, imaging tests, and atomic bomb radiation, the most common source is radon. Radon gas is a naturally occurring substance that is released when radioactive materials break down underground. Some radon seeps out into homes and the air. If it reaches levels above 4 picocuries/liter of air, it can increase your risk of lung cancer. Radon has no smell or appearance, but can be easily tested for in your home using an inexpensive test kit.
  • Exposure to hazardous materials and chemicals, such as asbestos. Workplace and everyday exposure to heavy metals like arsenic, cadmium, beryllium, and chromium or carcinogens like asbestos, tar, and soot can all cause lung cancer.
  • HIV infection. While the exact reason is unknown, people diagnosed with HIV or AIDS have as much as a two times greater risk.


Some factors, such as genetics and environmental exposures, cannot be controlled. But there are some preventive steps you can take:

  • Not smoking or quitting smoking as soon as possible
  • Limiting exposures to secondhand smoke, especially for children
  • Avoiding exposure to toxic materials, heavy metals, and radon

Research regarding lung cancer is ongoing. Some studies have also indicated that lifestyle factors protect against lung cancer, including:

  • Engaging in regular exercise
  • Maintaining a healthy weight
  • Eating a healthy diet high in vegetables, fruits, and healthy fats such as omega-3 fatty acids