That's the plain and simple explanation. Here's a short expansion: in its normal life, a cell will grow, divide, proliferate and then die, all the while meeting the needs of your body. When one or more of these cells begin to reproduce on their own, without serving their original purpose within the body, they form a tumor or a cancer. This is a mutation that researchers don't fully understand. Left unchecked, the cells will continue to reproduce and spread throughout the lung's tissue and then into the other vital organs of the body.

In 2004, the last year in which statistics were available at the time of the writing of this article, approximately 158,000 US citizens died from lung cancer, more than breast cancer, colon cancer, and prostrate cancer combined. While the numbers continue to drop every year as new strides are made in treating the disease and educating people, this is still represents a major health problem.

The primary cause of most lung cancers is ...

Yes, you guessed it ... cigarette smoking. Or more precisely, the inhalation of the carcinogens contained within the smoke. If a smoker is also exposed to radon in the environment, well, that's a ticking time bomb waiting to go off. Beyond these two contributors, there is a form of lung cancer called mesothelioma, which results from exposure to asbestos. However, cigarette smoke continues to be the major causes behind most forms of lung cancer.

Lung Cancer Symptoms

Here are few things to be looking for if you're concerned about the potential for lung cancer:

- Fatigue

- Shortness of breath and wheezing (dyspnoea)

- A cough that doesn't go away and gets worse over time

- Repeated problems with pneumonia or bronchitis

- Constant chest pain

- Coughing up blood (bloody sputum) (haemoptysis)

- Swelling of the neck and face

- Fever

- Loss of appetite and weight loss (anorexia)

- Hoarse voice

Other symptoms can include repeated bouts of pneumonia, changes in the shape of the fingertips, and swollen or enlarged lymph nodes (glands) in the upper chest and lower neck. Any and all of these symptoms may be caused by lung cancer or by a range of other medical conditions. That is, the presence of one or more of these symptoms does not automatically mean that you have lung cancer. Which is why you need to visit with your physician if you have any concerns at all.

Forms of Lung Cancer

The two primary forms of lung cancer are small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC).

Non-small cell lung cancer accounts for approximately 80% of diagnosed lung cancer cases. Within this category of lung cancer, there are three main sub-categories ... squamous cell carcinoma, adenocarcinomas, and large cell carcinomas. Sometimes two or even all three can appear together.

Small cell lung cancer is the less common of the two, which is good, because it's also the more deadly. Smoking is the primary cause behind this form of lung cancer. SCLC is aggressive and fast-moving. It rapidly metastasizes to other organs, and is often not discovered until the cancer is already widespread throughout the body.

The Good News

Since prevention is always better than cure, it's highly advisable to avoid the use tobacco. The best way to increase your odds of never encountering lung cancer is to never start smoking in the first place. However, if it's already too late for you, there's still some good news. You can gradually decrease your risk of the disease if you quit at any early age and your lungs are given 10 to 15 years to recover from the damage already imparted upon them.