Lung cancer is defined as the uncontrolled growth of abnormal cells in the lungs. Instead of developing into healthy lung tissue, these abnormal cells fail to carry out any of the functions of the lung. Their exponential growth is life-threatening as they may form tumors and prevent the healthy tissues from doing their job. Furthermore, these primary lung cancer cells may travel to other parts of the body. This results in metastatic lung cancer. Unfortunately, lung cancer signs and symptoms may take years to develop fully, and only manifest in later and more advanced stages of the disease.

For approximately 40 percent of cases, diagnosis is only possible in advanced stages. Even though the disease gives you little to no warning, there are a few lung cancer symptoms that you can watch out for. Those who are at a high risk for lung cancer are advised to sign up for early screening. Early detection of lung cancer symptoms makes a huge difference in your survival rate. If any of the following innocuous-looking symptoms persist, do not ignore them, and instead, seek professional help immediately.

1. Persistent Cough
Most people tend to ignore a persistent cough by saying that it is “just a cough”, and nothing to worry about. This oversight may cost you dearly. In general, a cough associated with a cold or respiratory infection disappears within a week or two. If your cough seems more stubborn and lingers on for a while after that, see your physician immediately. It does not matter if your cough is a dry one or produces mucus; if it is persistent, it could be one of the lung cancer symptoms.

2. Changes in Chronic Cough
If you are a smoker, chances are that you suffer from a chronic cough. If you do have a chronic cough, and notice any change in the way you are coughing, it could be one of the early lung cancer symptoms. Changes in cough need not always be as dramatic as coughing up blood. Even smaller, less obvious, changes such as a deeper or hoarser cough, or when you cough up more mucus than usual, may be lung cancer symptoms.

3. Chest Pain
Lung cancer is known to cause chest, shoulder, and/or back pain. This happens because of enlarged lymph nodes or due to the fact that the cancer has metastasized to the lining of the lungs, ribs or chest wall. If you’ve had a cough, you might associate the chest pain with the constant coughing, and may be inclined to ignore it. However, this is inadvisable. Head to your doctor, explain where and what kind of chest pain you are feeling, and get his/her professional opinion.

4. Breathing Difficulties
Breathing changes, as well as persistent shortness of breath, are possible lung cancer symptoms. If you find yourself unable to complete tasks such as climbing stairs that you could previously do without a hitch due to shortness of breath, do not ignore this change. Breathing changes may be the result of lung tumor fluid build-up in the chest, or because the cancer is blocking or narrowing an airway.

5. Wheezing/Whistling Sounds
This is one of those lung cancer symptoms that is often misinterpreted to mean something benign that can be easily handled. Your lungs make a wheezing or whistling sound when you breathe due to constricted or blocked airways. While this may happen due to asthma or allergies, do not ignore this problem as it is one of the possible lung cancer symptoms. Speak to your doctor, so he/she can confirm the cause of your wheezing.

6. Change in Voice
Most people suffer from a hoarser or raspier voice when they have a cold. However, if you find that your voice has changed dramatically, become deeper, hoarser, or raspier, and this change lasts for more than a couple of weeks, seek help immediately. This may be due to the tumor pressing against the nerve that controls the voice box or larynx.

Less Obvious Lung Cancer Symptoms

-Don’t ignore unexplained weight loss of more than 10 pounds. It may be one of the lung cancer symptoms, or a symptom of another cancer.

-Pain in the bones of the shoulder, arm or neck may mean that the lung cancer has spread to the bones.

-A persistent headache could be the result of lung cancer that has metastasized to the brain, or of a lung tumor pressing against the superior vena cava.

If you notice any of these probable lung cancer symptoms, seek help immediately.