One fourth of all people with lung cancer have no symptoms when the cancer is diagnosed. These cancers are usually identified incidentally when a chest X-ray is performed for another reason. The other three-fourths of people develop some symptoms. The symptoms are due to direct effects of the primary tumor; to effects of cancer spread to other parts of the body (metastases); or to disturbances of hormones, blood, or other systems.

Symptoms of lung cancer include cough, coughing up blood or rusty-colored phlegm, fatigue, unexplained weight loss, recurrent respiratory infections, hoarseness, new wheezing, and shortness of breath.

• A new cough in a smoker or a former smoker should raise concern for lung cancer.
• A cough that does not go away or gets worse over time should be evaluated by a health care provider.
• Coughing up blood (hemoptysis) occurs in a significant number of people who have lung cancer. Any amount of coughed-up blood should be evaluated by a health care provider.
• Pain in the chest area is a symptom in about one fourth of people with lung cancer. The pain is dull, aching, and persistent.
• Shortness of breath usually results from a blockage in part of the lung, collection of fluid around the lung (pleural effusion), or the spread of tumor through the lungs.
• Wheezing or hoarseness may signal blockage or inflammation in the lungs that may go along with cancer.
• Repeated respiratory infections, such as bronchitis or pneumonia, can be a sign of lung cancer.

Lung cancer typically doesn’t cause signs and symptoms in its earliest stages. Signs and symptoms of lung cancer typically occur only when the disease is advanced.

Signs and symptoms of lung cancer may include:

• A new cough that doesn’t go away
• Changes in a chronic cough or “smoker’s cough”
• Coughing up blood, even a small amount
• Shortness of breath
• Chest pain
• Wheezing
• Hoarseness
• Losing weight without trying
• Bone pain
• Headache

When to see a doctor

Make an appointment with your doctor if you have any signs or symptoms that worry you.

If you smoke and have been unable to quit, make an appointment with your doctor. Your doctor can recommend strategies for quitting smoking, such as counseling, medications and nicotine replacement products.

Causes

Smoking causes the majority of lung cancers — both in smokers and in people exposed to secondhand smoke. But lung cancer also occurs in people who never smoked and in those who never had prolonged exposure to secondhand smoke. In these cases, there may be no clear cause of lung cancer.

How smoking causes lung cancer

Doctors believe smoking causes lung cancer by damaging the cells that line the lungs. When you inhale cigarette smoke, which is full of cancer-causing substances (carcinogens), changes in the lung tissue begin almost immediately.

At first your body may be able to repair this damage. But with each repeated exposure, normal cells that line your lungs are increasingly damaged. Over time, the damage causes cells to act abnormally and eventually cancer may develop.

Risk factors

A number of factors may increase your risk of lung cancer. Some risk factors can be controlled, for instance, by quitting smoking. And other factors can’t be controlled, such as your family history.

Risk factors for lung cancer include:

• Smoking. Your risk of lung cancer increases with the number of cigarettes you smoke each day and the number of years you have smoked. Quitting at any age can significantly lower your risk of developing lung cancer.
• Exposure to secondhand smoke. Even if you don’t smoke, your risk of lung cancer increases if you’re exposed to secondhand smoke.
• Exposure to radon gas. Radon is produced by the natural breakdown of uranium in soil, rock and water that eventually becomes part of the air you breathe. Unsafe levels of radon can accumulate in any building, including homes.Radon testing kits, which can be purchased at home improvement stores, can determine whether levels are safe. If unsafe levels are discovered, remedies are available.
• Exposure to asbestos and other carcinogens. Workplace exposure to asbestos and other substances known to cause cancer — such as arsenic, chromium and nickel — also can increase your risk of developing lung cancer, especially if you’re a smoker.
• Family history of lung cancer. People with a parent, sibling or child with lung cancer have an increased risk of the disease.

Complications

Lung cancer can cause complications, such as:

• Shortness of breath. People with lung cancer can experience shortness of breath if cancer grows to block the major airways. Lung cancer can also cause fluid to accumulate around the lungs, making it harder for the affected lung to expand fully when you inhale.
• Coughing up blood. Lung cancer can cause bleeding in the airway, which can cause you to cough up blood (hemoptysis). Sometimes bleeding can become severe. Treatments are available to control bleeding.
• Pain. Advanced lung cancer that spreads to the lining of a lung or to another area of the body, such as a bone, can cause pain.Tell your doctor if you experience pain. Pain may initially be mild and intermittent, but can become constant. Medications, radiation therapy and other treatments may help make you more comfortable.
• Fluid in the chest (pleural effusion). Lung cancer can cause fluid to accumulate in the space that surrounds the affected lung in the chest cavity (pleural space).Fluid accumulating in the chest can cause shortness of breath. Treatments are available to drain the fluid from your chest and reduce the risk that pleural effusion will occur again.
• Cancer that spreads to other parts of the body (metastasis). Lung cancer often spreads (metastasizes) to other parts of the body, such as the brain and the bones.Cancer that spreads can cause pain, nausea, headaches, or other signs and symptoms depending on what organ is affected. Once lung cancer has spread to other organs, it’s generally not curable. Treatments are available to decrease signs and symptoms and to help you live longer

Preparing for your appointment

If you have signs and symptoms that worry you, start by seeing your family doctor. If your doctor suspects you have lung cancer, you’ll likely be referred to a specialist. Specialists who treat people with lung cancer can include:

• Doctors who specialize in treating cancer (oncologists)
• Doctors who diagnose and treat lung diseases (pulmonologists)
• Doctors who use radiation to treat cancer (radiation oncologists)
• Surgeons who operate on the lung (thoracic surgeons)
• Doctors who treat signs and symptoms of cancer and cancer treatment (palliative care specialists)

What you can do

Because appointments can be brief, and because there’s often a lot of ground to cover, it’s a good idea to be well-prepared. To help you get ready, try to:

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there’s anything you need to do in advance, such as restrict your diet.
• Write down any symptoms you’re experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment. Note when your symptoms began.
• Write down key personal information, including any major stresses or recent life changes.
• Make a list of all medications, vitamins or supplements you’re taking.
• Gather your medical records. If you’ve had a chest X-ray or a scan done by a different doctor, try to obtain that file and bring it to your appointment.
• Consider taking a family member or friend along. Sometimes it can be difficult to remember all the information provided during an appointment. Someone who accompanies you may remember something that you missed or forgot.
• Write down questions to ask your doctor.

Questions to ask if you’ve been diagnosed with lung cancer

Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out. For lung cancer, some basic questions to ask include:

• What type of lung cancer do I have?
• May I see the chest X-ray or CT scan that shows my cancer?
• What is causing my symptoms?
• What is the stage of my lung cancer?
• Will I need more tests?
• Should my lung cancer cells be tested for gene mutations that may determine my treatment options?
• Has my cancer spread to other parts of my body?
• What are my treatment options?
• Will any of these treatment options cure my cancer?
• What are the potential side effects of each treatment?
• Is there one treatment that you think is best for me?
• Is there a benefit if I quit smoking now?
• What advice would you give a friend or family member in my situation?
• What if I don’t want treatment?
• Are there ways to relieve the signs and symptoms I’m experiencing?
• Can I enroll in a clinical trial?
• Should I see a specialist? What will that cost, and will my insurance cover it?
• Are there brochures or other material that I can take with me? What websites do you recommend?

In addition to the questions that you’ve prepared to ask your doctor, don’t hesitate to ask other questions during your appointment.

What to expect from your doctor

Your doctor is likely to ask you a number of questions. Being ready to answer them may allow more time later to cover other points you want to address. Your doctor may ask:

• When did you first begin experiencing symptoms?
• Have your symptoms been continuous or occasional?
• How severe are your symptoms?
• Do you wheeze when breathing?
• Do you have a cough that feels like you’re clearing your throat?
• Have you ever been diagnosed with emphysema or chronic obstructive pulmonary disease?
• Do you take medications for shortness of breath?
• What, if anything, seems to improve your symptoms?
• What, if anything, appears to worsen your symptoms?

Testing healthy people for lung cancer

Several organizations recommend people with an increased risk of lung cancer consider annual computerized tomography (CT) scans to look for lung cancer. If you’re 55 or older and smoke or used to smoke, talk with your doctor about the benefits and risks of lung cancer screening.

Some studies show lung cancer screening saves lives by finding cancer earlier, when it may be treated more successfully. But other studies find that lung cancer screening often reveals more benign conditions that may require invasive testing and expose people to unnecessary risks and worry.

Tests to diagnose lung cancer

If there’s reason to think that you may have lung cancer, your doctor can order a number of tests to look for cancerous cells and to rule out other conditions. In order to diagnose lung cancer, your doctor may recommend:

• Imaging tests. An X-ray image of your lungs may reveal an abnormal mass or nodule. A CT scan can reveal small lesions in your lungs that might not be detected on an X-ray.
• Sputum cytology. If you have a cough and are producing sputum, looking at the sputum under the microscope can sometimes reveal the presence of lung cancer cells.
• Tissue sample (biopsy). A sample of abnormal cells may be removed in a procedure called a biopsy.

  Your doctor can perform a biopsy in a number of ways, including bronchoscopy, in which your doctor examines abnormal areas of your lungs using a lighted tube that’s passed down your throat and into your lungs; mediastinoscopy, in which an incision is made at the base of your neck and surgical tools are inserted behind your breastbone to take tissue samples from lymph nodes; and needle biopsy, in which your doctor uses X-ray or CT images to guide a needle through your chest wall and into the lung tissue to collect suspicious cells.

  A biopsy sample may also be taken from lymph nodes or other areas where cancer has spread, such as your liver.

  Lung cancer staging

Once your lung cancer has been diagnosed, your doctor will work to determine the extent (stage) of your cancer. Your cancer’s stage helps you and your doctor decide what treatment is most appropriate.

Staging tests may include imaging procedures that allow your doctor to look for evidence that cancer has spread beyond your lungs. These tests include CT scans, magnetic resonance imaging (MRI), positron emission tomography (PET) and bone scans. Not every test is appropriate for every person, so talk with your doctor about which procedures are right for you.

Stages of lung cancer

• Stage I. Cancer is limited to the lung and hasn’t spread to the lymph nodes. The tumor is generally smaller than 2 inches (5 centimeters) across.
• Stage II. The tumor at this stage may have grown larger than 2 inches, or it may be a smaller tumor that involves nearby structures, such as the chest wall, the diaphragm or the lining around the lungs (pleura). Cancer may also have spread to the nearby lymph nodes.
• Stage III. The tumor at this stage may have grown very large and invaded other organs near the lungs. Or this stage may indicate a smaller tumor accompanied by cancer cells in lymph nodes farther away from the lungs.
• Stage IV. Cancer has spread beyond the affected lung to the other lung or to distant areas of the body.

Small cell lung cancer is sometimes described as being limited or extensive. Limited indicates cancer is limited to one lung. Extensive indicates cancer has spread beyond the one lung.