Lung cancer – types, symptoms, causes and other risk factors

causes and symptoms of lung cancer

Lung cancer is one of the most common and most serious types of cancers. Every year in the United Kingdom, 44,500 people are diagnosed with this serious condition [1]. In the early stages of lung cancer there are no signs and symptoms but many people who suffer from this condition eventually develop symptoms such as:

  • An ache or pain when breathing or coughing
  • Unexplained tiredness and weight loss
  • Persistent breathlessness
  • Coughing up blood
  • A persistent cough

If you have noticed that you have some of the mentioned symptoms of lung cancer, then you need to talk with your doctor as soon as possible.

Types of lung cancer

Primary lung cancer is the type of lung cancer which begins in the lungs. Cancer which spreads to the lungs from another place of your body is known as secondary lung cancer. There are 2 main types of primary lung cancer which are classified by the type of cells in which the cancer starts. These types of lung cancers are next:

  1. Non – small – cell lung cancer: This is the most common type of lung cancer. It is accounting for more than 80% of cases. They can be either large – cell carcinoma, adenocarcinoma or squamous cell carcinoma.
  2. Small – cell lung cancer: This is a less common type of lung cancer. This type of lung cancer usually spreads faster than non – small – cell lung carcinoma.

The type of lung cancer from which you suffer, determines the type of treatment which you should use.

causes and symptoms of lung cancerSymptoms of lung cancer

In the early stages of lung cancer, there are not signs or symptoms but they develop as this condition progresses. Here are the main symptoms of lung cancer:

  • Loss of appetite or unexplained weight loss
  • Persistent tiredness or lack of energy
  • Persistent breathlessness
  • An ache or pain when breathing or coughing
  • Coughing up blood
  • Persistent chest infections
  • A long – standing cough that gets worse
  • A cough that does not go away after 2 or 3 weeks

Here are the less common symptoms of lung cancer:

  • Persistent chest or shoulder pain
  • Swelling of your face or neck
  • A hoarse voice
  • Wheezing
  • Difficulty swallowing or pain when swallowing
  • A high temperature, fever, of 100.4F (38C) or above
  • Changes in the appearance of your fingers, such as becoming more curved or their ends becoming larger (this condition is known as finger clubbing)

Causes of lung cancer

In the most cases this type of cancer is caused by smoking but also there are some cases when people who do not smoke, develop it. Here are the most common causes for lung cancer:

  • Smoking: The single biggest risk factor for lung cancer is smoking cigarettes. This factor is responsible for more than 85% of all cases [2]. Tobacco smoke has more than sixty different toxic substances which can lead to the development of cancer. It is known fact that these substances are cancer – producing (carcinogenic substances). There are many people who say that if you smoke more than 25 cigarettes per day, then you are 25 times more likely to get lung cancer compared to non – smokers.
  • Passive smoking: Passive smoking is the exposure to other people’s tobacco smoke. If you do not smoke but you are frequently passive smoker, then this will increase your risk of developing cancer. There are some studies in which is said that non – smoking women who live with a partner that is smoke are having 25% more chances of developing lung cancer compared to women who live with non – smoking partner. [3]
  • Radon: This is naturally occurring gas which comes from tiny amounts of uranium which is present in all soils and rocks. But also there are some cases when it can be found in buildings. If you breathe in this element, then it can damage your lungs, particularly if you are a smoker. In England is estimated that radon is responsible for about 3% of all lung cancer deaths [4].
  • Occupational exposure and pollution: There are many cases in which is said that the exposure to certain chemicals and substances which are used in several occupations and industries are linked to a slightly higher risk of developing lung cancer. [5,6] These substances and chemicals include:
  • Nickel
  • Silica
  • Coal and coke fumes
  • Cadmium
  • Beryllium
  • Asbestosis
  • Arsenic


[1] United Kingdom Lung Cancer Coalition. Ten years on in lung cancer: The changing landscape of the UK’s biggest cancer killer. Retrieved from

[2] Centers for Disease Control and Prevention. What are the risk factors for lung cancer? Retrieved from

[3] Hirayama T. Non-smoking wives of heavy smokers have a higher risk of lung cancer: A study from Japan. British Medical Journal (Clinical Research Edition). 1981;282(6259):183-5.

[4] United States Environmental Protection Agency. Health risk of radon. Retrieved from

[5] Cohen AJ. Air pollution and lung cancer: what more do we need to know? Thorax. 2003;58:1010-2.

[6] Kim HB, Shim JY, Park B, Lee YJ. Long-term exposure to air pollutants and cancer mortality: A meta-analysis of cohort studies. International Journal of Environmental Research and Public Health. 2018;15(11):2608.


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