Lung Cancer Causes, Symptoms, Diagnosis and Prevention

By Dr. Vivek Kumar Verma in Cancer Care / Oncology

Nov 09 , 2016 | 3 min read

More than 25% of lung cancer cases are diagnosed across the world. Surprisingly, many of them had already quit smoking before it is discovered that they are suffering from this disease.

Several patients think about what went wrong when they are diagnosed with this detrimental disease. It is not required to blame these people because it will make the situation worse and more difficult to handle. Rather, it is important that people should be made aware of the right way to approach this disease.

What causes Lung Cancer?

Lung cancer was not common prior to the 1930s but increased dramatically over the following decades as tobacco smoking increased. In many developing countries, the incidence of lung cancer is beginning to fall following public education about the dangers of cigarette smoking and the introduction of effective smoking-cessation programs. Nevertheless, lung cancer remains among the most common types of cancer in both men and women worldwide. The three causes are:


The incidence of lung cancer is strongly correlated with cigarette smoking, with about 90% of lung cancers arising as a result of tobacco use. The risk of lung cancer increases with the number of cigarettes smoked and the time over which smoking has occurred.

Tobacco smoke contains over 4,000 chemical compounds, many of which have been shown to be cancer-causing or carcinogenic. The two primary carcinogens in tobacco smoke are chemicals known as nitrosamines and polycyclic aromatic hydrocarbons.

Passive smoking

Passive smoking, or the inhalation of tobacco smoke by nonsmokers who share living or working quarters with smokers, also is an established risk factor for the development of lung cancer. Research has shown that nonsmokers who reside with a smoker have a 24% increase in risk for developing lung cancer when compared with nonsmokers who do not reside with a smoker. The risk appears to increase with the degree of exposure (number of years exposed and number of cigarettes smoked by the household partner).

Asbestos fibres

Asbestos fibres are silicate fibres that can persist for a lifetime in lung tissue following exposure to asbestos. The workplace was a common source of exposure to asbestos fibres, as asbestos was widely used in the past as both thermal and acoustic insulation. Today, asbestos use is limited or banned in many countries.

What are the possible Symptoms of Lung Cancer?

There are no apparent lung cancer symptoms at the time of diagnosis. Sometimes, the symptoms can occur due to cancer itself, i.e. from the metastatic spread of cancer beyond its origin in the lung or from paraneoplastic syndromes that result from the production of hormone-like substances. You can witness the following:

  • Cough
  • Shortness of breath
  • Wheezing
  • Chest pain
  • Coughing up blood

Other symptoms can be:

  • Shoulder pain
  • Hoarseness
  • Difficulty in swallowing
  • Vision changes
  • Weakness
  • Fatigue
  • Seizures
  • Drastic weight loss

Lung Cancer Diagnosis

  • Methods that allow early detection of cancers, such as the helical low-dose CT scan, also may be of value in the identification of small cancers that can be cured by surgical resection and prevented from becoming widespread, incurable, metastatic cancer.
  • Bronchoscopy and biopsy are important for establishing the diagnosis and staging of lung cancers.

When should one consult a doctor?

One should consult a Pulmonologist /Chest specialist if he or she develops the following symptoms:

  • A new persistent cough or worsening of an existing chronic cough,
  • Blood in the sputum,
  • Persistent bronchitis or repeated respiratory infections,
  • Chest pain,
  • Unexplained weight loss and/or fatigue,
  • Breathing difficulties such as shortness of breath or wheezing.

If you experience any of these symptoms, you shouldn't wait to visit a Pulmonologist /Chest specialist near you.

Check out - Thoracic Cancer Treatment in Delhi, India

How can lung cancer be prevented?

  • Cessation of smoking and eliminating exposure to tobacco smoke is the most important measure that can prevent lung cancer. Many products, such as nicotine gum, nicotine sprays, or nicotine inhalers, may be helpful to people trying to quit smoking.
  • Minimizing exposure to passive smoking also is an effective preventive measure.
  • Healthy lifestyle and Diet may also have a beneficial effect.
  • Avoid environmental pollution.